Nucleic acid molecules encoding alternansucrase

ABSTRACT

Nucleic acid molecules encoding an alternansucrase are provided. Moreover, vectors, host cells and plant cells transformed by the herein-described nucleic acid molecules and plants containing them are provided. Furthermore, methods are described for preparing transgenic plants which synthesize the carbohydrate alternan, because of the insertion of nucleic acid molecules encoding an alternansucrase. Moreover, methods for preparing alternan and products resulting from them are provided.

FIELD OF THE INVENTION

The present invention relates to nucleic acid molecules encoding an alternansucrase. Moreover, this invention relates to vectors, host cells and plant cells transformed with the herein-described nucleic acid molecules, and plants containing said cells. Moreover, methods for preparing transgenic plants which due to the insertion of DNA molecules encoding an alternansucrase, synthesize the carbohydrate alternan, are described. Furthermore, methods for preparing alternan are described.

Prior art documents, the disclosure content of which is included into the present application by reference thereto, are cited hereinafter.

Alternan is a polysaccharide composed of glucose units. The glucose units are linked to each other via α-1,3- and α-1,6-glycosidic bonds, and said two types of bonds predominantly appear alternatingly. However, alternan is not a linear polysaccharide, but may contain branches (Seymour et al., Carbohydrate Research 74, (1979), 41-62). Because of its physico-chemical properties, the possibilities of application of alternan both in the pharmaceutical industry, for instance as a carrier of pharmaceutically active ingredients and as an additive in the textile, cosmetics and food industry have been discussed (Lopez-Munguia et al., Enzyme Microb. Technol. 15, (1993), 77-85; Leathers et al., Journal of Industrial Microbiology & Biotechnology 18, (1997), 278-283). Moreover, it can be used as a substitute for gum arabic (Coté, Carbohydrate Polymers 19, (1992), 249-252).

Industry has a high interest in biotechnological methods for preparing oligosaccharides and polysaccharides, and in particular alternan which is hardly or not at all accessible to classical organic synthesis. Compared to the classical approach of organic synthesis chemistry, biotechnological processes offer advantages. For instance, enzymatically catalyzed reactions as a rule show much higher specificities (regio specificity, stereo specificity) and higher reaction speeds, proceed under milder reaction conditions and lead to higher yields. These factors are of outstanding importance in the preparation of new oligosaccharides and polysaccharides.

Alternan is prepared enzymatically with the use of enzymes possessing the biological activity of alternansucrases. Alternansucrases belong to the group of glucosyltransferases, which, starting from saccharose, are able to catalyze the formation of alternan and fructose. So far, alternansucrases have only been found in the bacterium Streptococcus mutans (Mukasa et al. (J. Gen. Microbiol. 135 (1989), 2055-2063); Tsumori et al. (J. Gen. Microbiol. 131 (1985), 3347-3353)) and in specific strains of the gram positive bacterium Leuconostoc mesenteroides where they are, as a rule, present together with other polysaccharide-forming enzymes, such as for instance dextran-forming dextransucrases, or together with polysaccharide-degrading enzymes, such as alternanases. Hence, the naturally occurring strains also produce dextran in addition to alternan.

So far, alternan has been prepared in a cell-free system using partially purified proteins or by fermentation using alternansucrase-producing strains of Leuconostoc mesenteroides.

Various purification methods for the purification of alternansucrases have been described (Lopez-Munguia et al., Enzyme Microb. Technol. 15 (1993), 77-85; Lopez-Munguia et al., Annals New York Academy of Sciences 613 (1990), 717-722; Coté and Robyt, Carbohydrate Research 101 (1982), 57-74). These methods are complex and relatively costly, and, as a rule, lead to low protein yields (Leathers et al., Journal of Industrial Microbiology & Biotechnology 18 (1997), 278-283). None of these methods allows highly pure alternansucrase protein to be produced, and therefore sequencing of the protein and the isolation of the corresponding DNA sequences have not been successful so far. If the alternansucrase protein purified according to these methods is used for in vitro preparation of alternan, then the dextransucrase protein residues contained in the alternansucrase preparation produce dextran impurities in the alternan produced. The separation of alternan and dextran is relatively time-consuming and costly (Leathers et al., Journal of Industrial Microbiology & Biotechnology 18 (1997), 278-283). Another disadvantage of the dextransucrase protein impurities contained in the enzyme preparation of alternansucrase protein is the fact that a part of the saccharose substrate is converted into dextran and not into alternan, which results in a reduction of the alternan yield.

The fermentative preparation by means of Leuconostoc also leads to the formation of product mixtures of alternan and dextran. In order to increase the amount of alternansucrase from Leuconostoc strains, mutants have been isolated, such as the mutant NRRL B-21138, which secrete the alternansucrase and lead to a higher proportion of the amount of alternansucrase formed relative to dextransucrase. However, if such mutants are fermented with sucrose, the alternan obtained continues to show dextran impurities (Leathers et al., Journal of Industrial Microbiology & Biotechnology 18 (1997), 278-283).

As can be seen from the prior art discussed above, it has not been possible to provide highly purified alternansucrase protein so far.

Hence, the present invention addresses the problem of providing means and methods allowing alternan to be prepared in a time-saving and inexpensive manner.

This problem is solved by the provision of the embodiments characterized in the patent claims.

SUMMARY OF THE INVENTION

Consequently, the present invention relates to a nucleic acid molecule encoding a protein possessing the biological activity of an alternansucrase selected from the group consisting of

(a) nucleic acid molecules encoding at least the mature form of a protein which comprises the amino acid sequence indicated in Seq. ID No. 2 or the amino acid sequence encoded by the cDNA contained in plasmid DSM 12666;

(b) nucleic acid molecules comprising the nucleotide sequence indicated in Seq. ID No. 1 or the nucleotide sequence of the cDNA contained in plasmid DSM 12666 or a corresponding ribonucleotide sequence;

(c) nucleic acid molecules encoding a protein, the amino acid sequence of which has a homology of at least 40% to the amino acid sequence indicated in Seq. ID No. 2;

(d) nucleic acid molecules, one strand of which hybridizes with the nucleic acid molecules as defined in (a) or (b);

(e) nucleic acid molecules comprising a nucleotide sequence encoding a biologically active fragment of the protein which is encoded by any one of the nucleic acid molecules as defined in (a), (b), (c) or (d); and

(f) nucleic acid molecules, the nucleotide sequence of which deviates because of the degeneration of the genetic code from the sequence of the nucleic acid molecules as defined in (a), (b), (c), (d) or (e).

Consequently, the present invention relates to nucleic acid molecules encoding proteins possessing the biological activity of an alternansucrase, said molecules preferably encoding proteins comprising the amino acid sequence indicated in Seq. ID No.2.

An enzyme possessing the enzymatic or biological activity of an alternansucrase (E.C. 2.4.1.140) is understood to mean an enzyme which is able to catalyze the conversion of saccharose into alternan and fructose. This conversion may occur both in the presence and absence of external acceptors (for instance maltose, isomaltose, isomaltotriose etc.). In the absence of external acceptors, alternansucrases starting from saccharose catalyze the release of fructose and high molecular alternan, a polysaccharide composed of glucose units, the backbone of which consists of glucose units predominantly connected to each other alternatingly by α-1,3- and α-1,6-glycosidic bonds. Concerning the percentage of α-1,3- and α-1,6-linked glucose units the literature displays different values. According to Mukasa et al. (J. Gen. Microbiol. 135 (1989), 2055-2063), alternan consists of 76 mol % α-1,3-linked glucose and 24 mol % α-1,6-linked glucose. Tsumori et al. (J. Gen. Microbiol. 131 (1985), 3347-3353) describe alternan as a polyglucan containing 49.1 mol % α-1,6-linked glucose and 33.9 mol % α-1,3-linked glucose with 13.6 mol % terminal glucose and 3.3 mol % α-1,3,6-branched glucose. In the presence of external acceptors, such as maltose, isomaltose, isomaltotriose and methyl-α-D-glucan, alternansucrase can catalyze the synthesis of α-D-glucan chains, in which the glucose residues are predominantly alternatingly connected by α-1,6- and α-1,3-glycosidic bonds, and the synthesis of fructose at these polysaccharide acceptors. Depending on the acceptor used, the products formed have different structures. The enzymatic activity of an alternansucrase can for instance be detected as described by Lopez-Munguia (Annals New York Academy of Sciences 613 (1990), 717-722) or as described in the examples of the present application.

The invention in particular relates to nucleic acid molecules containing the nucleotide sequence indicated under Seq. ID No. 1 or a part thereof, and preferably to molecules, which comprise the coding region indicated in Seq. ID No. 1 or corresponding ribonucleotide sequences.

Moreover, the present invention relates to nucleic acid molecules which encode an alternansucrase and the one strand of which hybridizes with one of the above-described molecules.

The present invention also relates to nucleic acid molecules which encode a protein, which has a homology, that is to say an identity of at least 40%, preferably at least 60%, preferably at least 70%, especially preferably at least 80% and in particular at least 90% to the entire amino acid sequence indicated in Seq. ID No. 2, the protein possessing the biological activity of an alternansucrase.

The present invention also relates to nucleic acid molecules, which encode an alternansucrase and the sequence of which deviates on account of the degeneration of the genetic code from the nucleotide sequences of the above-described nucleic acid molecules.

The invention also relates to nucleic acid molecules possessing a sequence which is complementary to the whole or a part of the above-mentioned sequences.

The nucleic acid sequence indicated in Seq. ID No. 1 for instance encodes an extracellular alternansucrase. Secretion is ensured by a signal sequence which comprises the first approximately 39 N-terminal amino acid groups of the Seq. ID No. 2. In certain circumstances it may be desirable for only the mature protein to be expressed without naturally occurring signal sequences and/or together with other signal sequences. Hence, the above-described nucleic acid molecules encode at least the mature form of a protein possessing the biological activity of an alternansucrase.

Within the present invention the term “hybridization” means hybridization under conventional hybridization conditions, preferably under stringent conditions, as for instance described in Sambrook et al., Molecular Cloning, A Laboratory Manual, 2^(nd) edition (1989) Cold Spring Harbour Laboratory Press, Cold Spring Harbour, N.Y. Within an especially preferred meaning the term “hybridization” means that hybridization occurs under the following conditions:

Hybridization buffer: 2×SSC; 10×Denhardt solution (Fikoll 400+PEG+BSA; ratio 1:1:1); 0.1% SDS; 5 mM EDTA; 50 mM Na₂HPO₄;250 μg/ml of herring sperm DNA; 50 μg/ml of tRNA; or

0.25 M of sodium phosphate buffer, pH 7.2;

1 mM EDTA

7% SDS

Hybridization temperature T=60° C.

Washing buffer: 2×SSC; 0.1% SDS

Washing temperature T=60° C.

Nucleic acid molecules which hybridize with the nucleic acid molecules of the invention can, in principle, encode alternansucrases from any organism expressing such proteins.

Nucleic acid molecules which hybridize with the molecules of the invention can for instance be isolated from genomic libraries of microorganisms. Alternatively, they can be prepared by genetic engineering or chemical synthesis.

Such nucleic acid molecules may be identified and isolated with the use of the molecules of the invention or parts of these molecules or reverse complements of these molecules, for instance by hybridization according to standard methods (see for instance Sambrook et al., 1989, Molecular Cloning. A Laboratory Manual, 2^(nd) edition, Cold Spring Harbor Laboratory Press, Cold Spring Harbor, N.Y.). Nucleic acid molecules possessing the same or substantially the same nucleotide sequence as indicated in Seq. ID No. 1 or parts thereof can, for instance, be used as hybridization probes. The fragments used as hybridization probes can also be synthetic fragments which are prepared by usual synthesis techniques, and the sequence of which substantially coincides with that of an inventive nucleic acid molecule.

The molecules hybridizing with the nucleic acid molecules of the invention also comprise fragments, derivatives and allelic variants of the above-described nucleic acid molecules encoding an alternansucrase of the invention. Herein, fragments are understood to mean parts of the nucleic acid molecules which are long enough to encode one of the described proteins, preferably showing the biological activity of an alternansucrase. In this connection, the term derivative means that the sequences of these molecules also differ from the sequences of the above-described nucleic acid molecules in one or more positions and show a high degree of homology to these sequences. In this context, homology means a sequence identity of at least 40%, in particular an identity of at least 60%, preferably more than 80% and particularly preferably more than 90%. Deviations from the above-described nucleic acid molecules may have been produced by deletion, substitution, insertion and/or recombination.

Preferably, the degree of homology is determined by comparing the respective sequence with the nucleotide sequence of the coding region of SEQ ID No.1. When the sequences which are compared do not have the same length, the degree of homology preferably refers to the percentage of nucleotide residues in the shorter sequence which are identical to nucleotide residues in the longer sequence. The degree of homology can be determined conventionally using known computer programs such as the ClustalW program (Thompson et al., Nucleic Acids Research 22 (1994), 4673-4680) distributed by Julie Thompson (Thompson@EMBL-Heidelberg.DE) and Toby Gibson (Gibson@EMBL-Heidelberg.DE) at the European Molecular Biology Laboratory, Meyerhofstrasse 1, D 69117 Heidelberg, Germany. ClustalW can also be downloaded from several websites including IGBMC (Institut de Génétique et de Biologie Moléculaire et Cellulaire, B.P.163, 67404 Illkirch Cedex, France; ftp://ftp-iabmc.u-strasbg.fr/pub/) and EBI (ftp://ftp.ebi.ac.uk/pub/software/) and all sites with mirrors to the EBI (European Bioinformatics Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SD, UK).

When using ClustalW program version 1.8 to determine whether a particular sequence is, for instance, 90% identical to a reference sequence according to the present invention, the settings are set in the following way for DNA sequence alignments:

KTUPLE=2, TOPDIAGS=4, PAIRGAP=5, DNAMATRIX:IUB, GAPOPEN=10, GAPEXT=5, MAXDIV=40, TRANSITIONS: unweighted.

For protein sequence alignments using ClustalW program version 1.8 the settings are the following: KTUPLE=1, TOPDIAG=5, WINDOW=5, PAIRGAP=3, GAPOPEN=10, GAPEXTEND=0.05, GAPDIST=8, MAXDIV=40, MATRIX=GONNET, ENDGAPS(OFF), NOPGAP, NOHGAP.

Furthermore, homology means preferably that the encoded protein displays a sequence identity of at least 40%, more preferably of at least 60%, even more preferably of at least 80%, in particular of at least 90% and particularly preferred of at least 95% to the amino acid sequence depicted under SEQ ID NO: 2.

Homology, moreover, means that there is a functional and/or structural equivalence between the corresponding nucleic acid molecules or proteins encoded thereby. Nucleic acid molecules which are homologous to the above-described molecules and represent derivatives of these molecules are, as a rule, variations of these molecules which represent modifications having the same biological function. They may be either naturally occurring variations, for instance sequences from other microorganisms, or mutations, and said mutations may have formed naturally or may have been produced by deliberate mutagenesis. Furthermore, the variations may be synthetically produced sequences. The allelic variants may be naturally occurring variants or synthetically produced variants or variants produced by recombinant DNA techniques.

In a further preferred embodiment the term “derivative” encompasses a nucleic acid molecule coding for a protein which comprises at least one, more preferably at least three, even more preferably at least five, in particular at least ten and particularly preferred at least twenty of the peptide motifs selected from the group consisting of

a) MKOQE (SEQ ID NO: 22),

b) KKVPV (SEQ ID NO: 23),

c) KDDEN (SEQ ID NO: 24),

d) IDGNL (SEQ ID NO: 25),

e) YVADS (SEQ ID NO: 26),

f) HLRKN (SEQ ID NO: 27),

g) NENTP (SEQ ID NO: 28),

h) NVDGY (SEQ ID NO: 29),

i) NPDLK (SEQ ID NO: 30),

j) SNDSG (SEQ ID NO: 31),

k) NTFVK (SEQ ID NO: 32),

l) ISGYL (SEQ ID NO: 33),

m) SNAAL (SEQ ID NO: 34),

n) RQYTD (SEQ ID NO: 35),

o) QLYRA (SEQ ID NO: 36),

p) DDKAP (SEQ ID NO: 37),

q) TRQYT (SEQ ID NO: 38),

r) ITFAG (SEQ ID NO: 39),

s) NQYKG (SEQ ID NO: 40),

t) LFLNA (SEQ ID NO: 41),

u) QVSDT (SEQ ID NO: 42),

v) LITLN (SEQ ID NO: 43),

w) GRYVH (SEQ ID NO: 44),

x) TAPYG (SEQ ID NO: 45),

y) VVDYQ (SEQ ID NO: 46),

z) LSGQE (SEQ ID NO: 47).

The proteins encoded by the different variants of the nucleic acid molecules of the invention possess certain characteristics they have in common. These include for instance enzymatic activity, molecular weight, immunological reactivity, conformation, etc., and physical properties, such as for instance the migration behavior in gel electrophoreses, chromatographic behavior, sedimentation coefficients, solubility, spectroscopic properties, stability, pH optimum, temperature optimum etc.

Alternansucrase (E.C. 2.4.1.140) is an enzyme belonging to the group of glucosyltransferases. So far, alternansucrase activity has not been found in plants, but only in the bacterium Streptococcus mutans (Mukasa et al. (J. Gen. Microbiol. 135 (1989), 2055-2063); Tsumori et al. (J. Gen. Microbiol. 131 (1985), 3347-3353)) and in specific strains of the bacterium Leuconostoc mesenteroides, for instance in NRRL B-1355, NRRL B-1498 and NRRL B-1501. As a rule, these strains contain different glucosyltransferases and secrete dextransucrases apart from alternansucrases if they are allowed to grow on saccharose-containing media. As a rule, these two sucrases possess a high binding affinity to the polysaccharides synthesized by them (Lopez-Munguia et al., Annals New York Academy of Sciences 613 (1990), 717-722) with the result that these polysaccharides must be separated from the protein in the purification of the enzymes from Leuconostoc mesenteroides strains grown on saccharose-containing medium (Lopez-Munguia et al., Enzyme Microb. Technol. 15 (1993), 77-85; Leathers et al., Journal of Industrial Microbiology & Biotechnology 18 (1997), 278-283).

In the absence of external acceptors, alternansucrases, starting from saccharose, catalyze the release of fructose and high molecular alternan, a polysaccharide which is composed of glucose units, and the backbone of which consists of glucose units predominantly linked to each other alternatingly by α-1,3- and α-1,6-glycosidic bonds and which according to light scattering measurement data should have a molecular weight of >10⁷ (Coté, Carbohydrate Polymer 19 (1992), 249-252). To date there has been no report of alternan possessing a terminal fructose residue. Nevertheless, the existence of a terminal fructose unit in alternan can not be completely excluded. Lopez-Munguia et al. (Enzyme Microb. Technol. 15 (1993) 77-85) describe that alternan is resistant to degradation by dextranases. However, it can be degraded by so-called alternanases, whereby ring-shaped oligomers of alternan of different polymerization degree can be produced (Biely et al., Eur. J. Biochem. 226 (1994), 633-639). Ultrasonic treatment of high molecular alternan allows the molecular weight of alternan to be reduced to <10⁶ (Coté, Carbohydrate Polymers 19 (1992), 249-252). If aqueous solutions of this ultrasonically treated alternan are prepared, then these solutions show rheological properties comparable to those of aqueous solutions of gum arabic. So-called “limit alternan” having a molecular weight of about 3500 can be produced by enzymatic degradation using isomaltodextranase from Arthrobacter globiformis (NRRL B-4425) (Cote, Carbohydrate Polymers 19 (1992), 249-252).

In the presence of external acceptors, such as for instance maltose, isomaltose, isomaltotriose and methyl-α-D-glucan, alternansucrase catalyzes at said saccharide acceptors the synthesis of α-D-glucan chains, in which the glucose moieties are predominantly alternatingly linked by α-1,6- and α-1,3 glycosidic bonds, and the synthesis of fructose. Depending on the acceptor used, the resulting products have different structures and a molecular weight which is lower than that of high molecular alternan and a polymerization degree of <15. Because of the polymerization degree, these products are often also referred to as oligoalternans (Pelenc et al., Sciences Des Aliments 11 (1991), 465-476). However, within the framework of the present invention these low molecular products which can be prepared in the presence of external acceptors are also to be referred to as alternan.

In the preparation of oligoalternans by means of partially purified alternansucrase protein, maltose is an acceptor (Lopez-Munguia et al., Enzyme Microb. Technol. 15 (1993), 77-85) producing high oligoalternan yields. Panose (degree of polymerization (d.p.) of 3) is the first acceptor product which is formed starting from maltose through the formation of an α-1,6-glycosidic bond.

In contrast thereto, isomaltose is a less effective acceptor which leads to lower yields of oligoalternan (Lopez-Munguia et al., Enzyme Microb. Technol. 15 (1993), 77-85).

Alternansucrase is relatively stable and has a half life period of 2 days in 50 mM of acetate buffer, pH 5.4 at 40° C. (Lopez-Munguia et al., Enzyme Microb. Technol. 15 (1993), 77-85). The enzyme shows maximum activity at a temperature of 40° C. and a pH value of 5.6 (Lopez-Munguia et al., Enzyme Microb. Technol. 15 (1993), 77-85).

In the absence of the substrate saccharose, alternansucrase catalyzes disproportionation reactions leading to a (partial) rearrangement of alternan. In particular when partially purified alternansucrase preparations containing dextransucrase contaminations were used to prepare oligoalternans, high disproportionation rates were found which lead to a complete rearrangement of oligoalternan (Lopez-Munguia et al., Enzyme Microb. Technol. 15 (1993), 77-85). For the molecular weight of alternansucrase according to SDS PAGE determination, different numerical values can be found: 135 kDa, 145 kDa, 173 kDa and 196 kDa, respectively (Leathers et al., Journal of Industrial Microbiology & Biotechnology 18 (1997), 278-283; Kim & Robyt, Enzyme Microb. Technol. 16 (1994), 659-664; Zhanley & Smith, Applied and Environmental Microbiology 61(3) (1995), 1120-1123).

The enzymatic activity of an alternansucrase can be shown for instance as described in Lopez-Munguia et al. (Annals New York Academy of Sciences 613 (1990), 717-722) or as described in the examples of the present application. One activity unit (1u) can be defined as the amount of enzyme leading to the release of 1 μmol of fructose within one minute.

The nucleic acid molecules of the invention can be DNA molecules, in particular genomic molecules. Moreover, the nucleic acid molecules of the invention may be RNA molecules. The nucleic acid molecules of the invention can be obtained for instance from natural sources or may be produced synthetically or by recombinant techniques.

The nucleic acid molecules of the invention allow host cells to be prepared which produce recombinant alternansucrase protein of high purity and/or in sufficient quantities, and genetically engineered plants possessing an activity of these enzymes leading to the formation of alternan in planta. Within the framework of the present invention the term “high purity” means that the protein according to the invention displays a degree of purity of at least 80%, preferably of at least 90%, even more preferably of at least 95%. Moreover, means and methods are provided which may be used for preparing alternan using host cells and/or for preparing recombinant alternansucrase protein. Consequently, the provision of the nucleic acid molecules of the invention permits the preparation of alternan of high purity by methods which are relatively inexpensive and consume relatively little time.

In a preferred embodiment, the nucleic molecules of the invention are derived from microorganisms, preferably from bacteria, more preferably from gram-positive bacteria and in particular preferably from bacteria belonging to the genus Leuconostoc. Nucleic acid molecules from bacteria belonging to the species Leuconostoc mesenteroides are particularly preferred.

The invention also relates to oligonucleotides specifically hybridizing to a nucleic acid molecule of the invention. Such oligonucleotides have a length of preferably at least 10, in particular at least 15, and particularly preferably of at least 50 nucleotides. They are characterized in that they specifically hybridize to the nucleic acid molecules of the invention, that is to say that they do not or only to a very minor extent hybridize to nucleic acid sequences encoding other proteins, in particular other glucosyltransferases. The oligonucleotides of the invention can be used for instance as primers for amplification techniques such as the PCR reaction or as a hybridization probe to isolate related genes.

Moreover, the invention relates to vectors, in particular plasmids, cosmids, viruses, bacteriophages and other vectors commonly used in gene technology, which contain the above-described nucleic acid molecules of the invention. In a preferred embodiment of the invention, the vectors of the invention lend themselves to the transformation of fungal cells or cells of microorganisms. Preferably, such vectors are suitable to transform plant cells. Particularly preferably, such vectors permit the integration of the nucleic acid molecules of the invention, possibly together with flanking regulatory regions, into the genome of the plant cell. Examples thereof are binary vectors which can be used in the Agrobacteria-mediated gene transfer, and some are already commercially available.

In another preferred embodiment, the nucleic acid molecules contained in the vectors are connected to regulatory elements ensuring the transcription and synthesis of a translatable RNA in prokaryotic or eukaryotic cells.

The expression of the nucleic acid molecules of the invention in prokaryotic or eukaryotic cells, for instance in Escherichia coli, is interesting because it permits a more precise characterization of the enzymatic activities of the enzymes encoded by these molecules. Moreover, it is possible to express these enzymes in such prokaryotic or eukaryotic cells which are free from interfering enzymes, such as dextransucrases or other polysaccharide-forming or polysaccharide-degrading enzymes. In addition, it is possible to insert different mutations into the nucleic acid molecules by methods usual in molecular biology (see for instance Sambrook et al., 1989, Molecular Cloning, A Laboratory Manual, 2^(nd) edition, Cold Spring Harbor Laboratory Press, Cold Spring Harbor, N.Y.), leading to the synthesis of proteins possibly having modified biological properties. On the one hand it is possible in this connection to produce deletion mutants in which nucleic acid molecules are produced by progressive deletions from the 5′ or 3′ end of the coding DNA sequence, and said nucleic acid molecules lead to the synthesis of correspondingly shortened proteins. Such deletions at the 5′ end of the nucleotide sequence for instance allow amino acid sequences to be identified which are responsible for the secretion of the enzyme in microorganisms (transit peptides). This permits the deliberate preparation of enzymes which are no longer secreted by the removal of the corresponding sequences, but remain within the cell of the corresponding host organism or are localized in other compartments, for instance in the plastids, mitochondria, vacuole, on account of the addition of other signal sequences.

On the other hand, the introduction of point mutations is also conceivable at positions at which a modification of the amino acid sequence for instance influences the enzyme activity or the control of the enzyme. In this manner, it is for instance possible to produce mutants which possess a modified stereo and regio selectivity or a modified Km value or which are no longer subject to the control mechanisms normally existing in the cell and realized via an allosteric control or covalent modification.

Moreover, mutants possessing a modified substrate or product specificity can be prepared. Furthermore, it is possible to prepare mutants having a modified activity-temperature-profile.

Furthermore, in the case of expression in plants, the insertion of mutations into the nucleic acid molecules of the invention allows the gene expression rate and/or the activity of the proteins encoded by the nucleic acid molecules of the invention to be increased.

For genetic engineering in prokaryotic cells, the nucleic acid molecules of the invention or parts of these molecules can be introduced into plasmids which permit mutagenesis or sequence modification by recombination of DNA sequences. Standard methods (see Sambrook et al., 1989, Molecular Cloning: A laboratory manual, 2^(nd) edition, Cold Spring Harbor Laboratory Press, NY, USA) allow base exchanges to be performed or natural or synthetic sequences to be added. DNA fragments can be connected to each other by applying adapters and linkers to the fragments. Moreover, engineering measures which provide suitable restriction sites or remove surplus DNA or restriction sites can be used. In those cases, in which insertions, deletions or substitutions are possible, in vitro mutagenesis, “primer repair”, restriction or ligation can be used. In general, a sequence analysis, restriction analysis and other methods of biochemistry and molecular biology are carried out as analysis methods.

Moreover, the invention relates to plasmid pAlsu-pSK (see FIG. 2 and Example 2) which was deposited at Deutsche Sammiung fur Mikroorganismen und Zelikulturen (DSMZ), Braunschweig, under the accession No. DSM 12666 on Feb. 4, 1999, and to the nucleic acid molecules contained in the insert of plasmid DSM 12666 and encoding a protein possessing the enzymatic activity of an alternansucrase. Moreover, the present invention also relates to nucleic acid molecules which hybridize to the insertion of plasmid DSM 12666. Also, the present invention relates to nucleic acid molecules the nucleotide sequence of which deviates from that of the nucleic acid molecules of the plasmid DSM 12666 insert, because of the degeneration of the genetic code. Furthermore, the present invention relates to nucleic acid molecules which have a homology, that is to say a sequence identity of at least 40%, preferably of at least 60%, more preferably of at least 80%, even more preferably of at least 90%, and most preferably of at least 95% to the sequence of the insertion of plasmid DSM 12666.

Another embodiment of the invention relates to host cells, in particular prokaryotic or eukaryotic cells transformed with an above-described nucleic acid molecule of the invention or with a vector of the invention, and to cells descended from such transformed cells and containing a nucleic acid molecule or vector of the invention.

According to another preferred embodiment, the host cells are cells of microorganisms. In the context of the present invention, the term “microorganism” comprises bacteria and all protists (e.g. fungi, in particular yeasts, algae) as defined Schlegel's “Aligemeine Mikrobiologie” (Georg Thieme Verlag, 1985, 1-2). A preferred embodiment of the invention relates to cells of algae and host cells belonging to the genera Aspergillus, Bacillus, Saccharomyces or Pichia (Rodriguez, Journal of Biotechnology 33 (1994), 135-146, Romanos, Vaccine, Vol. 9 (1991), 901 et seq.). A particularly preferred embodiment of the invention relates to E. coli cells. Alternansucrase is especially preferably secreted by the host cell. The preparation of such host cells for the production of recombinant alternansucrase can be carried out by methods known to a man skilled in the art. In a preferred embodiment of the invention, the host cells of the invention show no interfering enzymatic activities, such as those of polysaccharide-forming and/or polysaccharide-degrading enzymes.

An overview of different expression systems is for instance contained in Methods in Enzymology 153 (1987), 385-516, in Bitter et al. (Methods in Enzymology 153 (1987), 516-544) and in Sawers et al. (Applied Microbiology and Biotechnology 46 (1996), 1-9), Billman-Jacobe (Current Opinion in Biotechnology 7 (1996), 500-4), Hockney (Trends in Biotechnology 12 (1994), 456-463), Griffiths et al, Methods in Molecular Biology 75 (1997), 427-440). An overview of yeast expression systems is for instance given by Hensing et al. (Antonie van Leuwenhoek 67 (1995), 261-279), Bussineau et al. (Developments in Biological Standardization 83 (1994), 13-19), Gellissen et al. (Antonie van Leuwenhoek 62 (1992), 79-93, Fleer (Current Opinion in Biotechnology 3 (1992), 486-496), Vedvick (Current Opinion in Biotechnology 2 (1991), 742-745) and Buckholz (Bio/Technology 9 (1991), 1067-1072).

Expression vectors have been widely described in the literature. As a rule, they contain not only a selection marker gene and a replication-origin ensuring replication in the host selected, but also a bacterial or viral promoter, and in most cases a termination signal for transcription. Between the promoter and the termination signal there is at least one restriction site or a polylinker which enables the insertion of a coding DNA sequence. The DNA sequence naturally controlling the transcription of the corresponding gene can be used as the promoter sequence, if it is active in the selected host organism. However, this sequence can also be exchanged for other promoter sequences. It is possible to use promoters producing a constitutive expression of the gene and inducible promoters which permit a deliberate control of the expression of the postconnected gene. Bacterial and viral promoter sequences possessing these properties are described in detail in the literature. Regulatory sequences for the expression in microorganisms (for instance E. coli, S. cerevisiae) are sufficiently described in the literature. Promoters permitting a particularly high expression of the postconnected gene are for instance the T7 promoter (Studier et al., Methods in Enzymology 185 (1990), 60-89), lacUV5, trp, trp-lacUV5 (DeBoer et al., in Rodriguez and Chamberlin (Eds), Promoters, Structure and Function; Praeger, N.Y., (1982), 462-481; DeBoer et al., Proc. Natl. Acad. Sci. USA (1983), 21-25), Ip1, rac (Boros et al., Gene 42 (1986), 97-100). As a rule, the protein amounts are highest from the middle up to about the end of the logarithmic phase of the growth cycle of the microorganisms. Therefore, inducible promoters are preferably used for the synthesis of proteins. These promoters often lead to higher protein yields than do constitutive promoters. The use of highly constitutive promoters leads to the continuous transcription and translation of a cloned gene and thus often has the result that energy is lost for other essential cells functions with the effect that cell growth is slowed down (Bernard R. Glick/Jack J. Pasternak, Molekulare Biotechnologie (1995). Spektrum Akademischer Verlag GmbH, Heidelberg, Berlin, Oxford, p. 342). Therefore, in order to obtain an optimum amount of protein, a two-stage process is often used. First, the host cells are cultured under optimum conditions up to a relatively high cell density. In the second step, transcription is then induced depending on the type of promoter used. In this connection, a tac promoter is particularly suitable which can be induced by lactose or IPTG (=isopropyl-β-D-thiogalactopyranoside) (deBoer et al., Proc. Natl. Acad. Sci. USA 80 (1983), 21-25). Termination signals for transcription are also described in the literature.

The transformation of the host cell with DNA encoding an alternansucrase can, as a rule, be carried out by standard methods, as for instance described in Sambrook et al., (Molecular Cloning: A Laboratory Course Manual, 2^(nd) edition (1989) Cold Spring Harbor Press, New York; Methods in Yeast Genetics, A Laboratory Course Manual, Cold Spring Harbor Laboratory Press, 1990). The host cell is cultured in nutrient media meeting the requirements of the particular host cell used, in particular in respect of the pH value, temperature, salt concentration, aeration, antibiotics, vitamins, trace elements etc.

Moreover, the invention relates to proteins and biologically active fragments thereof, which are encoded by the nucleic acid molecules of the invention and to methods for their preparation, wherein a host cell according to the invention is cultured under conditions permitting the synthesis of the protein, and the protein is subsequently isolated from the cultured cells and/or the culture medium.

According to a preferred embodiment of the invention, the alternansucrase is a recombinantly produced protein. In the context of the present invention, this is a protein prepared by inserting a DNA sequence encoding the protein into a host cell and expressing it therein. The protein can then be isolated from the host cell and/or the culture medium.

The nucleic acid molecules of the invention now allow host cells to be prepared which produce recombinant alternansucrase protein of high purity and/or in sufficient amounts. Within the framework of the present invention the term “high purity” means that the protein according to the invention displays a degree of purity of at least 80%, preferably of at least 90%, even more preferably of at least 95%. The time-consuming and costly methods already mentioned above, whereby alternansucrase protein which to date can only be obtained from particular Leuconostoc strains can be purified from other components such as for instance dextransucrases, polysaccharides, are dispensed with, because alternansucrase can be produced in host cells not possessing any adverse polysaccharide-synthesizing activities. Moreover, host cells and vectors can also be used, which allow the alternansucrase protein to be produced in the absence of saccharose, with the result that an additional separation of the alternansucrase protein from polysaccharides is no longer necessary. Moreover, the selection of suitable host cells and vectors allows alternansucrase protein to be provided in sufficient amounts, which has not been possible with the systems so far described.

Alternansucrase produced by the host cells can be purified by conventional purification methods, such as precipitation, ion exchange chromatography, affinity-chromatography, gel filtration, HPLC Reverse Phase Chromatography etc. The modification of the nucleic acid molecules of the invention encoding an alternansucrase and expressed in the host cells, allows to produce a polypeptide in the host cell which is easier to isolate from the culture medium because of particular properties. Thus, the protein to be expressed can be expressed as a fusion protein with an additional polypeptide sequence, the specific binding properties of which permit the isolation of the fusion protein by affinity chromatography (e.g. Hopp et al., Bio/Technology 6 (1988), 1204-1210; Sassenfeld, Trends Biotechnol. 8 (1990), 88-93).

Another embodiment of the invention relates to proteins possessing the enzymatic activity of an alternansucrase, in particular that from microorganisms, preferably Gram-positive microorganisms, particularly microorganisms of the genus Leuconostoc, and particularly preferably that from Leuconostoc mesenteroides. The molecular weight of the protein indicated in Seq. ID No. 2, as determined by calculation, is 228.96 kDa. The invention also relates to alternansucrases which possess a molecular weight of 229 kDa±120 kDa, preferably 229 kDa±50 kDa, and particularly preferably 230 kDa±25 kDa. The molecular weight of the mature protein, as determined by calculation, is 224.77 kDa.

The provision of the nucleic acid molecules of the invention, for the first time, makes it possible to prepare alternansucrase-expressing plant cells by means of genetic engineering, which was not possible so far, because classical culturing methods do not allow bacterial and fungal genes to be expressed in plants.

The invention, therefore, also relates to transgenic plant cells transformed by a nucleic acid molecule of the invention or a vector of the invention or descended from such cells, the nucleic acid molecule which encodes the protein that has the biological activity of an alternansucrase being under the control of regulatory elements permitting the transcription of a translatable mRNA in plant cells.

The introduction of the activity of the proteins of the invention, for instance by expression of corresponding nucleic acid molecules, opens the possibility of producing alternan in plant cells correspondingly modified by genetic engineering. Hence, the expression of the nucleic acid molecules of the invention in plant cells is possible, allowing an additional, corresponding alternansucrase activity not present in the wild type to be introduced. Moreover, it is possible to modify the nucleic acid molecules of the invention according to methods known to a skilled person, in order to obtain alternansucrases of the invention which for instance possess modified temperature dependencies or substrate or product specificities. Such methods have already been described in more detail in a different context above.

A plurality of techniques is available by which DNA can be inserted into a plant host cell. These techniques include the transformation of plant cells by T-DNA using Agrobacterium tumefaciens or Agrobacterium rhizogenes as a transforming agent, the fusion of protoplasts, injection, electroporation of DNA, insertion of DNA by the biolistic approach and other possibilities.

The use of the Agrobacteria-mediated transformation of plant cells has been extensively investigated and sufficiently described in EP 120 516; Hoekema, In: The Binary Plant Vector System, Offsetdrukkerij Kanters B. V., Alblasserdam (1985), Chapter V; Fraley et al, Crit. Rev. Plant Sci. 4 (1993), 1-46 and An et al., EMBO J. 4 (1985), 277-287. Regarding the transformation of potatoes see for instance Rocha-Sosa et al. (EMBO J. 8 (1989), 29-33).

The transformation of monocotyledonous plants by means of Agrobacterium-based vectors has also been described (Chan et al., Plant Mol. Biol. 22 (1993), 491-506; Hiei et al., Plant J. 6 (1994) 271-282; Deng et al, Science in China 33 (1990), 28-34; Wilmink et al, Plant Cell Reports 11 (1992), 76-80; May et al., Bio/Technology 13 (1995), 486-492; Conner and Dormisse, Int. J. Plant Sci. 153 (1992), 550-555; Ritchie et al. Transgenic Res. 2 (1993), 252-265). An alternative system for transforming monocotyledonous plants is the transformation by the biolistic approach (Wan and Lemaux, Plant Physiol. 104 (1994), 37-48; Vasil et al., Bio/Technology 11 (1993), 1553-1558; Ritala et al., Plant Mol. Biol. 24 (1994) 317-325; Spencer et al., Theor. Appl. Genet. 79 (1990), 625-631), protoplast transformation, electroporation of partially permeabilized cells, insertion of DNA via glass fibers. The transformation of maize in particular has been repeatedly described in the literature (see for instance WO 95/06128, EP 0 513 849, EP 0 465 875, EP 29 24 35; Fromm et al, Biotechnology 8, (1990), 833-844; Gordon-Kamm et al., Plant Cell 2, (1990), 603-618; Koziel et al., Biotechnology 11 (1993), 194-200; Moroc et al., Theor. Appl. Genet. 80, (1990), 721-726).

The successful transformation of other types of cereals has also been described for instance of barley (Wan and Lemaux, supra; Ritala et al., supra, Krens et al., Nature 296 (1982), 72-74) and wheat (Nehra et al., Plant J. 5 (1994), 285-297). Generally, any promoter active in plant cells is suitable to express the nucleic acid molecules in plant cells. The promoter can be so chosen that the expression in the plants of the invention occurs constitutively or only in a particular tissue, at a particular time of plant development or at a time determined by external influences. The promoter may be homologous or heterologous to the plant.

Suitable promoters are for instance the promoter of 35S RNA of the Cauliflower Mosaic Virus (see for instance U.S. Pat. No. 5,352,605) and the ubiquitin-promoter (see for instance U.S. Pat. No. 5,614,399) which lend themselves to constitutive expression, the patatin gene promoter B33 (Rocha-Sosa et al., EMBO J. 8 (1989), 23-29) which lends itself to a tuber-specific expression in potatoes or a promoter ensuring expression in photosynthetically active tissues only, for instance the ST-LS1 promoter (Stockhaus et al., Proc. Natl. Acad. Sci. USA 84 (1987), 7943-7947; Stockhaus et al., EMBO, J. 8 (1989) 2445-2451), the Ca/b-promoter (see for instance U.S. Pat. No. 5,656,496, U.S. Pat. No. 5,639,952, Bansal et al., Proc. Natl. Acad. Sci. USA 89 (1992), 3654-3658) and the Rubisco SSU promoter (see for instance U.S. Pat. No. 5,034,322; U.S. Pat. No. 4,962,028) or the glutelin promoter from wheat which lends itself to endosperm-specific expression (HMW promoter) (Anderson, Theoretical and Applied Genetics 96, (1998), 568-576, Thomas, Plant Cell 2 (12), (1990), 1171-1180), the glutelin promoter from rice (Takaiwa, Plant Mol. Biol. 30(6) (1996), 1207-1221, Yoshihara, FEBS Lett. 383 (1996), 213-218, Yoshihara, Plant and Cell Physiology 37 (1996), 107-111), the shrunken promoter from maize (Maas, EMBO J. 8 (11) (1990), 3447-3452, Werr, Mol. Gen. Genet. 202(3) (1986), 471-475, Werr, Mol. Gen. Genet. 212(2), (1988), 342-350), the USP promoter, the phaseolin promoter (Sengupta-Gopalan, Proc. Natl. Acad. Sci. USA 82 (1985), 3320-3324, Bustos, Plant Cell 1 (9) (1989), 839-853) or promoters of zein genes from maize (Pedersen et al., Cell 29 (1982), 1015-1026; Quatroccio et al., Plant Mol. Biol. 15 (1990), 81-93). However, promoters which are only activated at a point in time determined by external influences can also be used (see for instance WO 93/07279). In this connection, promoters of heat shock proteins which permit simple induction may be of particular interest. Moreover, seed-specific promoters such as the USP promoter from Vicia faba which ensures a seed-specific expression in Vicia faba and other plants may be used (Fiedler et al., Plant Mol. Biol. 22 (1993), 669-679; Bäumlein et al., Mol. Gen. Genet. 225 (1991), 459-467). Moreover, fruit-specific promoters, such as described in WO 91/01373 may be used too.

Moreover, a termination sequence may be present, which serves to terminate transcription correctly and to add a poly-A-tail to the transcript, which is believed to have a function in the stabilization of the transcripts. Such elements are described in the literature (see for instance Gielen et al., EMBO J. 8 (1989), 23-29) and can be replaced at will.

Such cells can be distinguished from naturally occurring plant cells inter alia by the fact that they contain a nucleic acid molecule of the invention which does not naturally occur in these cells. Moreover, such transgenic plant cells of the invention can be distinguished from naturally occurring plant cells in that they contain at least one copy of the nucleic acid molecule of the invention stably integrated in their genome.

Moreover, the plant cells of the invention can preferably be distinguished from naturally occurring plant cells by at least one of the following features: If the inserted nucleic acid molecule of the invention is heterologous to the plant cell, then the transgenic plant cells are found to have transcripts of the inserted nucleic acid molecules of the invention. The latter can be detected for instance by Northern blot analysis. The plants cells of the invention preferably contain a protein encoded by an inserted nucleic acid molecule of the invention. This can be shown for instance by immunological methods, in particular by Western blot analysis.

Transgenic plant cells can be regenerated to whole plants according to methods known to a person skilled in the art.

The present invention also relates to the plants obtainable by regeneration of the transgenic plant cells of the invention. Furthermore, it relates to plants containing the above-described transgenic plant cells.

In most plants, the photoassimilates in the form of sugars formed during photosynthesis within a plant, i.e. mainly in the form of saccharose, are transported to the corresponding target organs. As saccharose is the substrate of the polymerization reaction of alternansucrase, all plants, both monocotyledonous and dicotyledonous can, in principle, be modified by the nucleic acid molecule of the invention in respect of alternansucrase expression.

The expression in plants of the nucleic acid molecules of the invention encoding a protein having the enzymatic activity of an alternansucrase can, for instance, be used to achieve a modification of the viscosity of the extracts possibly obtained from the plants, said modification being achieved by the synthesis of alternan. In this connection, for instance tomatoes are of interest. The expression of an alternansucrase in a tomato fruit leads to the synthesis of alternan and results in a modification of the viscosity of extracts obtained from these fruits for instance for the production of tomato puree or tomato ketchup.

The expression of the nucleic acid molecules of the invention is in particular advantageous in those organs of the plant which show a higher saccharose content or store saccharose. Such organs are for instance the beet of sugar beet or the cane of sugar cane. As these plants normally do not store any appreciable amounts of starch, the alternans synthesized by the alternansucrase from these plants could be isolated in the pure form.

The site where the biosynthesis of the saccharose in the plant cell occurs is the cytosol. The storage site, however, is the vacuole. During its transport into the storage tissue of the sugar beet or the potato or during its transport into the endosperm of seeds, the saccharose must pass the apoplast. Hence, all three compartments, i.e. the cytosol, the vacuole, the apoplast, lend themselves to the expression of the nucleic acid molecules for the synthesis of alternan. In addition, the plastids also lend themselves thereto, as could for instance be shown by the expression of bacterial fructosyl transferases in amyloplasts. Said fructosyl transferases which likewise require saccharose as a substrate, were able to mediate the formation of “amylofructan” in amyloplasts (Smeekens, Trends in Plant Science, Vol. 2, No. 8 (1997), 286-288).

In the case of starch-producing plants, such as potatoes and maize, where the starch biosynthesis and starch storage normally take place in the amyloplasts, an expression of the alternansucrase in apoplasts, in the cytosol or in the vacuole would lead to an additional synthesis of oligosaccharides and/or polysaccharides in these compartments, which can mean an overall increase in the yield.

As in the case of potatoes the starch synthesized in the amyloplasts can be separated from the alternan synthesized in the apoplast, in the cytosol or in the vacuole, the very same plant can be used to recover starch and alternan.

Moreover, transgenic potato and maize plants are known, the starch synthesis of which in the tubers and grains, respectively, is completely inhibited due to the inhibition of ADP-glucose-pyrophosphorylase by an antisense construct. In the case of potatoes, soluble sugars, in particular saccharose and glucose, accumulate instead, for instance in the tubers (Müller-Röber et al., EMBO J. 11 (1992), 1229-1238). Alternan can be prepared in the cytosol, the vacuole or apoplast of these plants by the expression of an alternansucrase which uses saccharose as a substrate.

Therefore in another embodiment of the invention the plant cells of the invention are further characterized by a reduced ADP glucose pyrophosphorylase (AGPase) activity compared to corresponding cells from wild-type plants.

DNA molecules encoding AGPase are well known to the person skilled in the art and described for example in Müller-Röber et al. (Mol. Gen. Genet. 224 (1) (1990), 136-146). By using DNA molecules encoding an AGPase it is possible to produce plants by means of recombinant DNA techniques (for example by an antisense, a ribozyme or a cosuppression approach) showing a reduced AGPase activity. Furthermore AGPase mutants, for example from maize (brittle-2 and shrunken-2), with reduced AGPase activity are known to the person skilled in the art.

The term “reduced” means preferably a reduction of AGPase activity of at least 10%, more preferably of at least 50% and even more preferably of at least 80% in comparison to corresponding wild-type cells.

The activity of an AGPase can be determined according to Müller-Röber et al. (Mol. Gen. Genet. 224 (1) (1990), 136-146) or to methods known to a person skilled in the art.

The reaction which is catalyzed by alternansucrase is distinguished by the fact that a glucose moiety is transferred directly from saccharose to an existing carbohydrate acceptor. By contrast, in the case of plants, the biosynthesis of linear glucans from saccharose, proceeds in such a way that the saccharose is first separated into glucose and fructose, which are then each converted into activated intermediate ADP-glucose. The glucose moiety is transferred by the enzyme starch-synthase from the ADP glucose to an already existing glucan, whereby ADP is released. The conversion of saccharose into two ADP glucose molecules requires several energy consuming reactions. Therefore, the energy consumption of the reaction catalyzed by alternansucrase is substantially lower than the energy consumption in the synthesis of polysaccharides from saccharose in plant cells, which can lead to an increased yield of synthesized oligo and/or polysaccharides in plants containing the nucleic acid molecules of the invention.

In the expression of the nucleic acid molecules in plants there exists in principle the possibility that the synthesized protein can be localized in any compartment of the plant cell (e.g. in the cytosol, plastids, vacuole, mitochondria) or the plant (e.g. in the apoplast). In order to achieve the localization in a particular compartment, the coding region must, where necessary, be linked to DNA sequences ensuring localization in the corresponding compartment. The signal sequences used must each be arranged in the same reading frame as the DNA sequence encoding the enzyme.

In order to ensure the location in the plastids it is conceivable to use one of the following transit peptides: of the plastidic Ferredoxin: NADP+ oxidoreductase (FNR) of spinach which is enclosed in Jansen et al. (Current Genetics 13 (1988), 517-522). In particular, the sequence ranging from the nucleotides −171 to 165 of the cDNA Sequence disclosed therein can be used, which comprises the 5′non-translated region as well as the sequence encoding the transit peptide. Another example is the transit peptide of the waxy protein of maize including the first 34 amino acid residues of the mature waxy protein (Klösgen et al., Mol. Gen. Genet. 217 (1989), 155-161). It is also possible to use this transit peptide without the first 34 amino acids of the mature protein. Furthermore, the signal peptides of the ribulose bisposphate carboxylase small subunit (Wolter et al., Proc. NatI. Acad. Sci. USA 85 (1988), 846-850; Nawrath et al., Proc. Natl. Acad. Sci. USA 91 (1994), 12760-12764), of the NADP malate dehydrogenase (Gallardo et al., Planta 197 (1995), 324-332), of the glutathione reductase (Creissen et al., Plant J. 8 (1995), 167-175) or of the R1 protein Lorberth et al. (Nature Biotechnology 16, (1998), 473-477) can be used.

In order to ensure the location in the vacuole it is conceivable to use one of the following transit peptides: the N-terminal sequence (146 amino acids) of the patatin protein (Sonnewald et al., Plant J. 1 (1991), 95-106) or the signal sequences described by Matsuoka und Neuhaus, Journal of Experimental Botany 50 (1999), 165-174; Chrispeels und Raikhel, Cell 68 (1992), 613-616; Matsuoka und Nakamura, Proc. Natl. Acad. Sci. USA 88 (1991), 834-838; Bednarek und Raikhel, Plant Cell 3 (1991), 1195-1206; Nakamura und Matsuoka, Plant Phys. 101 (1993), 1-5.

In order to ensure the location in the mitochondria it is for example conceivable to use the transit peptide described by Braun et al.(EMBO J. 11, (1992), 3219-3227). In order to ensure the location in the apoplast it is conceivable to use one of the following transit peptides: signal sequence of the proteinase inhibitor 11-gene (Keil et al., Nucleic Acid Res. 14 (1986), 5641-5650; von Schaewen et al., EMBO J. 9 (1990), 30-33), of the levansucrase gene from Erwinia amylovora (Geier and Geider, Phys. Mol. Plant Pathol. 42 (1993), 387-404), of a fragment of the patatin gene B33 from Solanum tuberosum, which encodes the first 33 amino acids (Rosahl et al., Mol Gen. Genet. 203 (1986), 214-220) or of the one described by Oshima et al. (Nucleic Acid Res. 18 (1990), 181).

The nucleic acid sequence indicated in Seq. ID No. 1 encodes an extracellular alternansucrase. Secretion is ensured by a signal sequence comprising the first approximately 39 N-terminal amino acid residues of the Seq. ID No. 2.

The transgenic plants may, in principle, be plants of any plant species, that is to say they may be monocotyledonous and dicotyledonous plants. Preferably, the plants are useful plants cultivated by man for nutrition or for technical, in particular industrial, purposes. They are preferably starch-storing plants, for instance cereal species (rye, barley, oat, wheat, millet, sago etc.), rice, pea, marrow pea, cassava and potato; tomato, rape, soybean, hemp, flax, sunflower, cow pea or arrowroot, fiber-forming plants (e.g. flax, hemp, cotton), oil-storing plants (e.g. rape, sunflower, soybean) and protein-storing plants (e.g. legumes, cereals, soybeans). The invention also relates to fruit trees and palms. Moreover, the invention relates to forage plants (e.g. forage and pasture grasses, such as alfalfa, clover, ryegrass) and vegetable plants (e.g. tomato, lettuce, chicory) and ornamental plants (e.g. tulips, hyacinths). Sugar-storing and/or starch-storing plants are preferred. Sugar cane and sugar beet,. and potato plants, maize, rice, wheat and tomato plants are particularly preferred.

A further subject of the invention is a method for the production of transgenic plant cells and transgenic plants which in comparison to non-transformed wildtype cells/non-transformed wildtype plants synthesize alternan. In this method the expression and/or the activity of proteins encoded by the nucleic acid molecules of the invention is increased in comparison to corresponding wild-type cells/wildtype plants which do not show any alternansucrase expression and/or activity. In particular, such a method comprises the expression of a nucleic acid molecule according to the invention in plant cells. The nucleic acid molecule according to the invention is preferably linked to a promoter ensuring expression in plant cells. In a particularly preferred embodiment the method comprises the introduction of a nucleic acid molecule according to the invention into a plant cell and regeneration of a plant from this cell.

Such an increase in expression may, e.g., be detected by Northern blot analysis. The increase in activity may be detected by testing protein extracts for their alternansucrase activity derived from plant cells. The enzymatic activity of an alternansucrase can be measured, for instance, as described in Lopez-Munguia et al. (Annals New York Academy of Sciences 613, (1990), 717-722) or as described in the examples of the present application.

The invention also relates to propagation material of the plants of the invention. The term “propagation material” comprises those components of the plant which are suitable to produce offspring vegetatively or generatively. Suitable means for vegetative propagation are for instance cuttings, callus cultures, rhizomes or tubers. Other propagation material includes for instance fruits, seeds, seedlings, protoplasts, cell cultures etc. The preferred propagation materials are tubers and seeds. The invention also relates to harvestable parts of the plants of the invention such as, for instance, fruits, seeds, tubers or rootstocks.

Another embodiment of the invention relates to methods for preparing alternan which comprise the step of extracting and isolating alternan from a plant of the invention.

The extraction and isolation of alternan from a plant of the invention may be carried out by standard methods, such as precipitation, extraction and chromatographic methods.

Moreover, the present invention relates to alternan obtainable from a plant of the invention or from propagation material of the invention.

Moreover, the present invention relates to a method for preparing alternan and/or fructose, wherein a host cell of the invention secretes an alternansucrase into a saccharose-containing culture medium and alternan and/or fructose is/are isolated from the culture medium.

A preferred embodiment of the method of the invention uses an alternansucrase recombinantly produced and secreted by the host cell into the culture medium, thus avoiding the necessity of breaking up the cells and purifying the protein further, because the secreted protein can be obtained from the supernatant. The residual components of the culture medium can be removed by methods usual in processing technology, such as dialysis, reverse osmosis, chromatographic methods, etc. The same applies to the concentration of the protein secreted into the culture medium. The secretion of proteins by microorganisms is normally mediated by N-terminal signal peptides (signal sequence, leader-peptide, transit peptide). Proteins possessing this signal sequence are able to penetrate the cell membrane of the microorganism. A secretion of proteins can be achieved by adding the DNA sequence encoding this signal peptide to the corresponding region encoding the alternansucrase.

The natural signal peptide of the expressed alternansucrase is preferred, that of the alternansucrase from Leuconostoc mesenteroides NRRL B 1355 (see the first approximately 25 to 45 N-terminal amino acid residues of Seq. ID No. 2) is particularly preferred.

The signal peptide of α-CGTase from Klebsiella oxytoca M5A1 (Fiedler et al., J. Mol. Biol. 256 (1996), 279-291) or a signal peptide as encoded by the nucleotides 11529-11618 of the sequence available under the GenBank accession number X86014 is most preferred.

The preparation of alternan and/or fructose requires neither activated glucose derivatives nor co-factors, as are necessary in most synthesis reactions for polysaccharides occurring within the cells. Hence, alternansucrase-secreting microorganisms can be cultured in saccharose-containing medium, the secreted alternansucrase leading to a synthesis of alternan and fructose in the culture medium.

Contrary to host cells from Leuconostoc mesenteroides, which secrete alternansucrase by nature, the host cells used according to the invention have the advantage that they do not secrete proteins possessing adverse polysaccharide-synthesizing side reactions, such as dextransucrase, with the result that outside the host cell, apart from alternan, no other polysaccharides can be formed which, as a rule, can be separated from alternan only by costly and time-consuming procedures. Moreover, the host cells according to a preferred embodiment of the invention do not have any adverse polysaccharide-degrading side activities, which would otherwise lead to losses in the yield of the alternan produced.

The method of the invention yields fructose apart from alternan. Fructose can be used for the inexpensive isolation of so-called “high-fructose-containing syrups” (HFCS). Conventional methods for preparing fructose on the one hand provide for the enzymatic break down of saccharose by means of an invertase or for the break down of starch into glucose units, mostly brought about by acid hydrolysis, and for subsequent enzymatic conversion of the glucose into fructose by glucose isomerases. However, both methods lead to mixtures of glucose and fructose. The two components must subsequently be separated from each other by chromatographic methods.

The separation of the two reaction products of the method of the invention, or the separation of the reaction products from the substrate saccharose can be achieved for example with the use of membranes permitting the penetration of fructose, but not the penetration of saccharose and/or alternans. If continuous removal of fructose via such a membrane is provided for, a more or less complete conversion of saccharose occurs.

The isolation of alternan and fructose can be carried out by standard methods or can be carried out as for instance described in the working examples.

According to one embodiment of the method, the host cells originate from microorganisms, preferably from Escherichia coli.

In another embodiment, the method of the invention works with fungal host cells, in particular cells of yeasts, such as Saccharomyces cerevisiae. Yeast cells producing alternan in saccharose-containing medium because of the enzymatic activity of an alternansucrase, cannot be readily used, as yeasts secrete an invertase which breaks down the extracellular saccharose. The yeasts take up the resulting hexoses via a hexose transporter. However, one yeast strain has been described (Riesmeier et al. EMBO J. 11 (1992), 4705-4713) which carries a defective suc2 gene, and therefore cannot secrete invertase. Moreover, these yeast cells do not contain a transportation system able to import saccharose into the cells. If such a strain is so modified by means of the nucleic acid molecules of the invention that it secretes an alternansucrase into the culture medium, then fructose and alternan will be synthesized in saccharose-containing medium. The resulting fructose can subsequently be taken up by the yeast cells.

In another preferred embodiment of this method the host cell of the invention is present in an immobilized form.

As a rule, host cells are immobilized by inclusion of the cells in a suitable material, such as alginate, polyacrylamide, gelatin, cellulose or chitosan. However, adsorption or covalent binding of the cells to a carrier material is also possible (Brodelius and Mosbach, Methods in Enzymology Vol. 135 (1987), 222-230) An advantage of the immobilization of cells is that it allows substantially higher cell densities to be achieved than does culturing in liquid culture. This results in a higher productivity. Moreover, the costs for agitation and aeration of the culture decrease as do the costs for measures to maintain sterility. Another important aspect is the possibility of a continuous alternan production with the result that unproductive phases regularly occurring in fermentation processes can be avoided or at least greatly reduced.

Another embodiment of the invention relates to a method for preparing alternan and/or fructose, wherein

a) a saccharose-containing solution is contacted with a protein of the invention under conditions permitting the conversion of saccharose into alternan and/or fructose; and

b) alternan and/or fructose is/are isolated from the solution.

In this embodiment, the invention thus relates to a method for preparing alternan and/or fructose in vitro by means of a cell-free enzyme preparation. In this case, microorganisms which for instance secrete alternansucrase are cultured up to the stationary phase in a saccharose-free medium permitting the formation of alternansucrase protein. After removing the cells from the culture medium by centrifugation, the secreted enzyme can be recovered from the supernatant. The enzyme can subsequently be added to saccharose-containing solutions in order to synthesize alternan and/or fructose. Compared to the above-described synthesis of alternan in a system not freed from cells, this method offers the advantage that the reaction conditions can be controlled better and the reaction products are substantially purer and easier to purify. The purification of the protein can be carried out as already described above.

A preferred embodiment of the method of the invention uses a purified alternansucrase. Purified alternansucrase is understood to mean an enzyme which is largely free from cell components of the cells in which the protein is synthesized and shows no contamination with proteins possessing polysaccharide-synthesizing activities (e.g. dextransucrases) or degrading activities, and/or no contamination with (polysaccharide) acceptors. The term “purified alternansucrase” preferably means an alternansucrase possessing a degree of purity of at least 70%, preferably at least 85%, and particularly preferably at least 95%.

The use of a purified protein for preparing alternan and/or fructose offers various advantages. Compared to methods working with partially purified protein extracts, the reaction medium of the method of the invention does not contain any residues of the production strain (microorganism) which is used for the purification of the protein or for its preparation by genetic engineering.

Moreover, the use of the purified protein is advantageous for food and pharmaceutical industry applications. Thanks to the fact that the reaction medium is defined in its composition and freed from all unnecessary components, the product is likewise more precisely defined in respect of its components. In consequence of this, the procedure for obtaining food and pharmaceutical industry approval of these products produced by genetic engineering requires substantially less documentation, especially since these products should not show any traces of a transgenic microorganism.

Moreover, contrary to the so far described in vitro methods in cell free systems using partially purified alternansucrase preparations, the method of the invention using a purified alternansucrase has the advantage that it allows highly pure alternan to be prepared without the occurrence of dextransucrase and dextran contaminations, because of the high purity of the protein of the invention. Moreover, the method of the invention permits the production of alternan in high yields, without losses caused for instance by adverse side reactions of a dextransucrase, which would convert part of the substrate saccharose into undesired dextran, the separation of which from alternan would only be possible using time-consuming and expensive methods.

The method of the invention produces fructose in addition to alternan. The fructose can be used for the inexpensive recovery of so-called “high-fructose-containing syrups” (HFCS). The method of the invention yields products of high purity, because of the use of a purified alternansucrase. Hence, compared to conventional methods for preparing HFCS from maize starch, which comprise costly process steps for removing the buffer salts by ion exchange, (Crabb and Mitchinson, TIBTECH 15 (1997), 349-352) the method of the invention does not require an expensive purification of the fructose.

Another preferred embodiment of the method of the invention uses a recombinantly prepared alternansucrase.

According to another preferred embodiment, the enzyme possessing the enzymatic activity of an alternansucrase is immobilized on a carrier material. Immobilization of the alternansucrase offers the advantage that the enzyme being the catalyst of the synthesis reaction can be easily recovered from the reaction mixture and reused several times. As the purification of enzymes is normally costly and time consuming, immobilization and reutilization of the enzymes allow for a substantial cost saving. Another advantage is the degree of purity of the reaction products not containing any residual protein.

There are many carrier materials available for the immobilization of proteins, and coupling to the carrier material can be made via covalent or non-covalent bonds (for an overview see: Methods in Enzymology 135, 136, 137). Widely used carrier materials include for instance agarose, alginate, cellulose, polyacrylamide, silica or nylon.

According to another embodiment of the invention, the alternansucrase (immobilized on a carrier material) is present between two membranes, one of which allows fructose, but not saccharose and alternan to penetrate, the other one of which allows saccharose, but not alternan to penetrate. The supply with substrate occurs through the membrane which allows saccharose to penetrate it. The synthesized alternan remains in the space between the two membranes and the released fructose can be continuously removed from the reaction equilibrium via the membrane which only allows fructose to penetrate it. Such an arrangement permits an efficient separation of the reaction products, and thus the production of pure fructose.

Moreover, the separation of fructose by ion exchange chromatography has been described (“Starch Hydrolysis Products, Worldwide Technology, Production, and Application”, Edited by F. W. Schenck, R. E. Hebeda, (1992), VCH Publishers, Inc., New York).

Thus, the use of alternansucrases for preparing pure fructose on the one hand involves the advantage that the relatively inexpensive substrate saccharose can be used as the starting material, and on the other hand the fructose can be isolated easily from the reaction mixture without additional enzymatic conversions or chromatographic methods.

Moreover, the invention relates to methods for preparing alternan and/or fructose, wherein

a) a saccharose-containing solution is contacted with a protein of the invention and acceptor molecules under conditions permitting the conversion of saccharose to alternan and/or fructose; and

b) alternan and/or fructose is/are isolated from the solution.

Within the framework of the present invention an acceptor molecule is understood to mean a molecule at which an alternansucrase is able to catalyze a chain-extending reaction. The acceptor which can be added to the reaction mixture at the beginning of the reaction is preferably a carbohydrate or a carbohydrate derivative. The use of external acceptors leads to the production of low molecular products which are to be designated alternan in the context of the present invention. The carbohydrate acceptor is preferably an oligo or polysaccharide, in particular a branched polysaccharide, such as dextrin, glycogen or amylopectin, preferably a linear polysaccharide, and particularly preferably a saccharide selected from the group consisting of maltose, isomaltose, isomaltotriose and methyl-α-D-glucan. If an extension of the alternan chain at these acceptors occurs, then products are formed which have a higher molecular weight than the educt. Where maltose, isomaltose, isomaltotriose and methyl-α-D-glucan are used, one obtains products which have a lower molecular weight than the alternan that can be prepared in the absence of external carbohydrate acceptors.

The size of the molecular weight of the oligoalternans prepared depends on the saccharose/acceptor ratio used. For instance the degree of polymerization of the products increases as the saccharose/isomaltose ratio increases.

Moreover, the saccharose/acceptor ratio has an influence on the oligoalternan yield. For instance, the oligoalternan yield increases as the saccharose/isomaltose ratio decreases.

The hitherto described methods for producing oligoalternan with the use of alternansucrases which the authors claim have been purified (Pelenc et al., Sciences Des Aliments 11 (1991), 465-476) only yielded product mixtures of oligoalternan and oligodextran, in the presence of the carbohydrate acceptor maltose. In this case, the synthesis of oligodextran is presumably attributable to dextransucrase-contaminations of the alternansucrase preparation. Compared to this method, the method of the invention offers the advantage that the use of recombinantly produced alternansucrase protein not containing any dextransucrase contaminants permits the preparation of oligoalternan without the simultaneous formation of oligodextran. Thus, the method of the invention makes it possible to provide oligoalternan, without requiring additional costly purification steps for separating oligodextran.

According to another preferred embodiment, the enzyme possessing the enzymatic activity of an alternansucrase is immobilized on a carrier material.

According to another preferred embodiment of the method of the invention, a recombinantly produced alternansucrase is used.

Moreover, the present invention relates to end products containing alternan. In this context, end products are understood to mean cosmetic products, preferably food products, fodder and particularly preferably pharmaceutical products.

Finally, the present invention relates to a method for preparing the afore-mentioned products comprising one of the above-described alternan manufacturing methods of the invention and the formulation of the thus obtained alternan in a form which is suitable for one of the afore-mentioned applications of the corresponding product.

These and other embodiments are disclosed and obvious to a skilled person and embraced by the description and the examples of the present invention. Additional literature regarding one of the above-mentioned methods, means and applications, which can be used within the meaning of the present invention, can be obtained from the state of the art, for instance from public libraries for instance by the use of electronic means. This purpose can be served inter alia by public databases, such as the “medline”, which are accessible via internet. Other databases and addresses are known to a skilled person and can be obtained from the internet. An overview of sources and information regarding patents and patent application in biotechnology is contained in Berks, TIBTECH 12 (1994), 352-364.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1:

Linear map of the entire sequence region which was cloned after the screening of a genomic library of Leuconostoc mesenteroides NRRL B 1355 by the corresponding overlapping fragments of the clones AS-19B1, AS-19B2, AS-28B and AS-29Ba.

FIG. 2:

Plasmid map pAlsu-pSK

FIG. 3:

HPLC chromatogram: Preparation of oligoalternan in the presence of maltose (Example 2).

FIG. 4:

Plasmid map pAlsu-pET24a

FIG. 5:

SDS PAGE with subsequent assay of sucrase activity (see Example 6) The following protein extracts are used

1+2) E. coli BL21 (DE3) containing pAlsu-pET24a-3

3+4) E. coli BL21 (DE3) containing pAlsu-pET24a-7

5+6) E. coli BL21 (DE3) containing pAlsu-pET24a-21

7+8) E. coli BL21 (DE3) containing pET24a

1, 3, 5, 7) culture before induction with IPTG

2, 4, 6, 8) culture at the end of culturing

FIG. 6:

HPLC chromatogram of dextran T10

FIG. 7:

HPLC chromatogram of dextran T10 after dextranase digestion

FIG. 8:

HPLC chromatogram of oligoalternan

FIG. 9:

HPLC chromatogram of oligoalternan after dextranase digestion.

FIG. 10:

Map of the expression cassette including the polylinker of the plasmid pBinAR-N.

FIG. 11: Plasmid map pat-Alsu-Hyg.

FIG. 12:

Plasmid map fnr-Alsu-Hyg.

DETAILED DESCRIPTION OF THE INVENTION EXAMPLES

Vectors used in the Examples:

1. pBinAR-N

By the use of standard methods (Sambrook et al., Molecular cloning: A laboratory manual, 2nd issue; Cold Spring Harbor Laboratory Press, N.Y., USA (1989)) we introduced a different polylinker (see FIG. 10) between the 35S Promoter and the OCS-Terminator into the plasmid pBinAR (Höfgen und Willmitzer, Plant Science 66 (1990), 221-230). The resulting plasmid was called pBinAR-N.

2. pBinAR-Hyg-N

Via standard methods (Sambrook et al., Molecular cloning: A laboratory manual, 2nd issue; Cold Spring Harbor Laboratory Press, N.Y., USA (1989)) we isolated an EcoRI/HinDIII-fragment from pBinAR-N containing the 35S Promoter, the polylinker and the OCS-Terminator. This fragment was then ligated into the same restriction sites of plasmid pBIB-Hyg (Becker, Nucleic Acids Research 18 (1990), 203). The resulting plasmid was called pBinAR-Hyg-N.

3. pBinAR-pat-Hyg

By using the oligonucleotides Sp-pat-5′ and Sp-pat-3′ (s. SEQ ID Nos. 48 and SEQ ID No. 49) we amplified DNA molecules coding for the leader peptide of the patatin protein from potato (see SEQ ID No. 50, which differs from the sequence used by Sonnewald et al. Plant J. 1 (1991), 95-106 ) via a PCR approach using plasmid pgT5 (Rosahl et al., Mol. Gen. Genet. 203 (1986), 214-220; Sonnewald et al., Plant J. 1 (1991), 95-106) as a template. The resulting PCR products were cut by the restriction enzymes Xbal and Sall and then ligated into the plasmid pBinAR-Hyg-N which was linearized before by using the restriction enzymes Spel and Sall. The resulting plasmid was called pBinAR-pat-Hyg.

PCR Conditions:

Buffer and polymerase from Boehringer Mannheim (Pwo Polymerase No. 1644947)

DNA 0,2 ng 10x Buffer + MgSO₄ 5 μl dNTPs (je 10 mM) 1 μl Primer Sp-pat-5′ 120 nM Primer Sp-pat-3′ 120 nM Pwo Polymerase 1,0 units Distilled water ad 50 μl Reaction conditions: Step 1 95° C. 2:30 min Step 2 95° C. 0:30 min Step 3 64° C. 0:30 min Step 4 72° C. 0:30 min (plus 1 sec per cycle) Step 5 72° C. 5:00 min.

The steps 2 to 4 were repeated 35 times in a cyclical manner.

4. pBinAR-FNR-Hyg

By using the oligonucleotides Sp-fnr-5′ and Sp-fnr-3 (see SEQ ID No. 51 and 52) we amplified DNA molecules coding for the transit peptide of the FNR protein from spinach via a PCR approach using plasmid p6SocFNR-15 (Jansen et al., Current Genetics 13, (1988), 517-522) as a template. The resulting PCR products were cut by Xbal and Sall and then cloned into the Spel/Sall-opened pBinAR-Hyg-N. Resulting plasmid was called pBinAR-fnr-Hyg.

PCR Conditions:

Buffer and polymerase from Gibco BRL (Platinum Taq DNA Polymerase High Fidelity No. 1304-011)

DNA 0,2 ng 10x Buffer 5 μl MgSO4 2,0 μl dNTPs (per 10 mM) 1 μl Primer Sp-fnr-5′ 150 nM Primer Sp-fnr-3′ 150 nM Taq Platinum Hifi Polymerase 1,5 units distilled water ad 50 μl Reaction conditions: Step 1 95° C. 2:30 min Step 2 95° C. 0:30 min Step 3 58° C. 0:30 min Step 4 68° C. 0:20 min (plus 1 sec per cycle) Step 5 68° C. 3:00 min

The steps 2 to 4 were repeated 35 times in a cyclical manner.

Example 1 Cloning of Alternansucrase from Leuconostoc Mesenteroides NRRL-B1355

Isolation and Sequencing of Alternansucrase

The strain Leuconostoc mesenteroides NRRL-B1355 was cultured in 1 l of Lactobacilli MRS Broth (Difco) complemented with 5% saccharose at 28° C. for two days. After the culture was subjected to centrifugation at 20,000×g for 30 minutes, the supernatant was admixed with the same volume of 10% trichloro acetic acid and stirred at 4° C. for 16 hours. This solution was then subjected to centrifugation at 10,000×g for 30 minutes. The thus obtained precipitate was dissolved in 4.5 ml of 40 mM Tris-HCl, pH 8.8, and subsequently neutralized with (about 0.5 ml) 2 M Tris-base. This protein solution was given to the company Toplab Gesellschaft fur angewandte Biotechnologie mbH, Martinsried, Germany, for protein sequencing. At this company, the protein solution was electrophoretically separated in SDS polyacrylamide gel, the gel was stained with Coomassie Blue and the staining was subsequently removed by 10% acetic acid. For the enzymatic digestion of the protein, the protein bands were cut from the gel, pressed through a sieve and fragmented (pores 30 μm×100 μm). The crushed gel was then washed with half concentrated incubation buffer (12.5 mM Tris, 0.5 mM EDTA pH 8.5) for 2 minutes. Subsequently, it was subjected to centrifugation, the buffer was removed and the gel was dried in the “Speedvac” for one hour (about 5% residual water, rubber-like). Subsequently, a solution of endoproteinase LysC in 400 μl 12.5 mM Tris/HCl, pH 8.5 (enzyme: protein=1: 10) and 0.1% of laurylmaltosite was prepared. 200 μl of this solution were added to the sample and incubated in the heat block shaker at 37° C. overnight. In order to elute the peptide fragments, a one hour incubation with 1% TFA was carried out, twice, followed by centrifugation, and subsequently by elution with 10% formic acid, 20% isopropanol, 60% acetonitrile for 3 hours. The peptide fragments obtained were then separated from each other by HPLC (column Superspher 60 RP select B (Merck, Darmstadt) 2 mm×125 mm; buffer A 0.1% trifluoro acetic acid, buffer B: 0.085% TFA in acetonitrile; flow rate: 0.2 ml/min; gradient: 5-60% in 60 min; detection at 206 nm. The peptide fragments obtained were then sequenced in an automatic sequencer Procise 492 (Applied Biosystems, PE); the procedure being the stepwise Edman degradation in a modification according to Hunkapiller (Hunkapiller et al., Meth. Enzymol. 91 (1983), 399-413). Six different peptide sequences (see Seq. ID Nos. 5 to 9, Seq. ID No. 21) were identified which were designated lysC-66, IysC-67, lysC-82, IysC-83, lysC-88 and “N-terminus”.

Preparation of a Genomic DNA Library from Leuconostoc Mesenteroides NRRL B1355

Leuconostoc mesenteroides NRRL-B1355 (purchased from ATCC) was cultured in 100 ml YT medium (Sambrook et al, loc. cit.) additionally containing 2% (w/v) of glucose and 50 mM sodium phosphate buffer pH 7.0, at 28° C. for 36 hours. After harvesting the cells by centrifugation, genomic DNA was isolated according to Ausubel et al. (Current Protocols in Molecular Biology, Volume 1, Greene and John Wiley & Sons (1994), USA).

100 μg of genomic DNA from Leuconostoc mesenteroides NRRL-B1355 were partially digested with 0.001 units of the restriction enzyme Sau3A for 30 minutes, subsequently extracted with phenol:chloroform:isoamyl alcohol. (25:24:1) and precipitated with ethanol. 2.5 μg of the partially digested DNA obtained from Leuconostoc mesenteroides NRRL-B1355 were ligated with T4 DNA ligase in 1 μg of the BamHl-cut and dephosphorylated vector pBKCMVBamHl (Stratagene) under the conditions indicated by the manufacturer (Stratagene, pBK phagemid vectors instruction manual & T4 DNA ligase ligation kit). 2 μl of the ligation mixture were packaged with Gigapack III Gold (Stratagene) according to the instructions of the manufacturer and stored after the amount of phage content had been determined.

Preparation of the Probe for Isolating the Alternansucrase Gene

From the peptide sequences lysC-66 (Seq. ID No. 5), lysC-67 (Seq. ID No. 6), IysC-82 (Seq. ID No. 7), lysC-83 (Seq. ID No. 8) and lysC-88 (Seq. ID No. 9) obtained after tryptic digestion of the purified alternansucrase protein (see above) the peptides lysC-82 and lysC-83, after having undergone reverse translation, were selected for the synthesis of degenerated oligonucleotides (Seq. ID No. 10, Seq. ID No. 11). Said oligonucleotides served as primers in a PCR reaction on genomic DNA of NRRL-B1355. All positions within oligonucleotides depicted as N were replaced by inosin in the primer synthesis.

PCR Reaction Conditions

The reaction mixture was prepared with the buffers supplied for Taq polymerase (Company GibcoBRL). Reaction mixture:

Taq Polymerase (Gibco) DNA 100 ng (genomic NRRL-B1355) DNTPs 2.5 mM for each nucleotide primer 10 μl of a solution containing 0.2 μMol 10 fold buffer 5 μl magnesium chloride 2 mM polymerase 1 unit water ad 50 μl Step 1 95° C. 3′ Step 2 95° C. 1′ Step 3 58° C. 2′ Step 4 72° C. 2′ Step 5 72° C. 10′ 

40 Repetitions of Steps 2 to 4

An 837 bp fragment (Seq. ID No. 12) resulting from this PCR reaction, the ends of which were blunted with T4 DNA polymerase, was cloned into the Smal-cut pBlueSkript vector (Stratagene). The resulting plasmid was designated pAlsu-PCR-lysc82/83. After sequencing of the insert and computer-aided translation into the corresponding protein sequences, a data base comparison was carried out in the Swiss Prot data base. This comparison showed homologies to known glycosyl transferases (P49331, P11001, P68987, P13470, P27470, P29336).

About 5,000 phages of the genomic DNA library of Leuconostoc mesenteroides NRRL-B1355 were plated out using the bacterial strains and nutrient solutions indicated by the manufacturer (Stratagene), and after incubation at 37° C. for 12 hours were transferred to nitrocellulose filters. This was followed by denaturation of the phages by immersion of the nitrocellulose filters in 1.5 m sodium chloride, 0.5 M caustic soda solution for 2 minutes and neutralization of the filters by immersion in 1.5 M sodium chloride, 0.5 M Tris-HCl, pH 8.0 for 5 minutes. After rinsing the filters in 0.2 M Tris-HCl, 2×SSC, the phage DNA was bound to the membranes by UV cross link (Stratalinker of the company Stratagene, 120,000 μJ for 30 seconds). The filters were incubated in a prehybridization solution (5×SSC, 0.5% BSA, 5×Denhardt, 1% SDS, 40 mM sodium phosphate buffer, pH 7.2, 100 mg/l herring sperm-DNA, 25% formamide) at 42° C. for 6 hours. 30 ng of the isolated insert from the plasmid pAlsu-PCR-lysc82/83 were radioactivley labeled by means of a multiprime kit (Boehringer Mannheim) using α-³²p dCTP (ICN Biomedicals). This radioactive probe was added to the prehybridization mixture and the filters were incubated in this hybridization mixture at 42° C. overnight. After removal of the hybridization mixture the filters were washed three times in a washing solution (0.1×SSC, 0.5% SDS) at 55° C. for 15 minutes. An X-ray film (Kodak) was then placed on the filter for 18 hours. Phage colonies, producing hybridization signals, were identified, isolated, resuspended in SM medium and then again plated out in a dissolution such that they could be recognized as single plaques. After these phages were transferred to nitrocellulose filters and subjected to further treatment and hybridization under conditions as described above, hybridizing phages were obtained as individual isolates by means of the radioactive gene probe used. After in vivo excision of the isolated phages in accordance with the manufacturer's instructions (Stratagene) the clones AS-19B1 and AS-19B2 could be isolated as plasmids. After complete sequencing of both clones (Agowa) (Seq. ID No. 13, Seq. ID No. 14) both sequences showed an 1008 bp overlap. The joining of Seq. ID No. 13 with Seq. No. 14 followed by computer aided translation of all possible reading frames allowed a continuous reading frame, starting with the codon ATG (corresponding to the bases 678 to 680 in Seq. ID No. 1), to be identified. As no stop codon could be found in this composed reading frame, additional clones were isolated in order to obtain the complete coding sequence of alternansucrase.

Therefore, about 5,000 phages of the genomic DNA library of L. mesenteroides NRRL-B1355 were again examined for hybridization by means of a clone AS-19B2 subfragment radioactively labeled using the multiprime kit (Boehringer Mannheim), as described above. The hybridization probe was prepared with the use of the HindlIl (restriction site in the insert of AS-19B2)/Sall (cuts the pBKCMV phagemid vector in the polylinker)-fragment from AS-19B2. Said fragment contains 372 bases of the 3′ end of the sequences encoding the above-described reading frame. The screening of the phage library, singling out, and transformation of the phages into plasmids was carried out under the above-described conditions. After complete sequence analysis of the thus isolated clones AS-28B (see Seq. ID No. 15) and AS-29Ba (Seq. ID No. 16) it was possible to identify an overlap of 960 identical bases (corresponding to bases 4863 to 5823 in Seq. ID No. 1) between clones AS-19B2 (Seq. ID No. 14) and AS-28B and an overlap of 567 identical bases (corresponding to bases 5256 to 5823 in Seq. ID No. 1) between clones AS-19B2 and AS-29Ba (Seq. ID No. 16). Clones AS-28B and AS-29Ba have 1523 identical bases (corresponding to bases 5256 to 6779 in Seq. ID No. 1). After computer-aided joining of clones AS-19B1, AS-19-B2 and AS-28B a continuous reading frame starting with codon ATG (bases 678 to 680 on the complete sequence) appeared. This reading frame also does not contain a stop codon. After the joining of clones AS-1 9B1, AS-1 9B2, AS-28B and AS-29Ba it was possible to identify a reading frame starting with the codon “ATG” (corresponding to bases 678 to 680 in Seq. ID No. 1) and ending with “TM” (corresponding to bases 6849 to 6851 in Seq. ID No. 1) encoding 2057 amino acids. In addition to the coding region, the entire isolated and identified DNA sequence of the composed clones (Seq. ID Nos. 13-16) contains 677 bases in the 5′ region and 2469 bases in the 3′ region which represent sequences not encoding alternansucrase (see FIG. 1).

Example 2 Construction of Plasmid pAlsu-pSK for the Transformation of E. Coli and Test of the Protein Extracts for Enzymatic Activity

Plasmids AS-19B1, AS-19B2, AS-28B and AS-29Ba (see Example 1) were joined in the following manner: A Notl-(restriction site in the polylinker of vector pBK CMV, company Novagen)/Clal-fragment of clone AS-19B1 was inserted into the vector pBluescript SK (company Stratagene) at the same restriction sites (=first cloning step). Consecutive insertion of the Clal/Xhol fragment from AS-19B2, Xhol/Mlul fragment from AS-28B and Mlul/BsaBI (BsaBI-cut fragment cloned into the blunted Apal restriction site of the vector) fragment of AS-28B into the clone obtained from the first cloning step produced plasmid pAlsu-pSK (see FIG. 2). This plasmid contains the complete coding sequence of the alternansucrase from Leuconostoc mesenteroides NRRL-B1355 as well as non-coding sequences of 677 bp (promoter region) in the 5′ region and 539 bp in the 3′ region (Seq. ID No. 17).

Plasmid pAlsu-pSK was then transformed in E. coli (DH5α company Fermentas). The bacteria were then cultured at 27° C. for two days in 50 ml “Terrific broth” (the composition of which is described in Sambrook et al., Molecular Cloning, A Laboratory Manual, 2^(nd) edition (1989) Cold Spring Harbor Laboratory Press, Cold Spring Harbor, N.Y. (supplemented with 0.5% glucose) or in a fermentation medium having the following composition: KH₂PO₄ 1.5 g/l, (NH₄)₂SO₄ 5.0 g/l, NaCl 0.5 g/l, Na-citrate 1.0 g/l, Fe²⁺SO₄×7 H₂O, 0.075 g/l, yeast extract 0.5 g/l, tryptone 1.0 g/l, glucose 15.0 g/l, MgSO₄×7, H₂O 0.3 g/l, CaCl₂×2 H₂O 0.014 g/l, mineral salts 10 ml/l, H₃BO₃ 2.5 g/l, CoCl₂×6 H₂O 0.7 g/l, CuSO₄ ×5 H₂O 0.25 g/l, MnCl₂×4 H₂O, 1.6 g/l, ZnSO₄×7 H₂O 0.3 g/l, Na₂MoO₄×2 H₂O 0.15 g/l, vitamin B1 (thiamine) 0.005 g/l.

All cultures contained 100 mg/l ampicillin. The cells were then harvested by centrifugation, resuspended in 2 ml 50 mM Na-phosphate buffer pH 7.2 and crushed by a French Press. Subsequently, they were again subjected to centrifugation to remove solid particles of the crushed cells, and the supernatant (hereinafter referred to as (protein) extract) was used after sterilfiltration (Sterivex GV 0.2 μm, millipore) for further analyses.

In vitro Preparation of Alternan by Means of Protein Extracts

For the in vitro preparation of alternan, 200 μl each of the extracts obtained were examined in 2 ml each of 100 mM Na-citrate buffer pH 6.5 and 20% (w/v) saccharose for activity in the presence and absence of 100 μl of 10 mM maltose. The reaction mixture was incubated at 37° C. for 24 hours. In the subsequent precipitation with the same volume of ethanol in the absence of maltose no precipitable polymer was found. In the batch containing maltose, HPLC chromatography (Dionex PA-100 column, running buffer 150 mM NaOH, elution buffer 150 mM NaOH+3 M sodium acetate buffer gradient) showed the formation of oligomers (see FIG. 3).

Activity Gel

20 ml each of the individual protein extracts were applied to a 6% SDS-PM gel and separated at a current strength of 20 mA per gel. (Before application to the gels, the extracts were not incubated at 95° C.). Subsequently, the extracts were examined for sucrase activity according to the method of Miller and Robyt (Analytical Biochemistry 156 (1986), 357-363).

The control (dextransucrase NRRL-B-512F, see Example 3 for its preparation) showed polymerizing activity. The protein extracts of the above-described E. coli cells containing the plasmid pAlsu-pSK, did not show any polymer-forming activity.

Example 3 Cloning and Expression of Dextransucrase from Leuconostoc Mesenteroides NRRL-B512F

Isolation of Genomic DNA

Leuconostoc mesenteroides NRRL-B512F (obtained from ATCC) was cultured at 28° C. for 48 hours in YT-medium (Sambrook et al., Molecular Cloning: A Laboratory Course Manual, 2^(nd) edition (1989), Cold Spring Harbor Press, New York) additionally containing 1 % of saccharose and 50 mM sodium phosphate buffer pH 7.0. After harvesting the cells by centrifugation, genomic DNA was isolated according to Ausubel et al. (Current Protocols in Molecular Biology, Volume 1, Greene and John Wiley & Sons (1994), USA).

PCR Amplification of the Dextransucrase Gene and Cloning in pET24a

For the recombinant expression of dextransucrase in E. coli, the gene encoding dextransucrase was cloned in the expression vector pET24a (Novagen) after PCR amplification. For this purpose, an Eagl restriction site was introduced at the 5′ end of the sequences encoding the dextransucrase and an Xhol restriction site at the 3′ end, together with the PCR primers used (5′b512-1: 5′-ACTgCggCCgCATgCCATTTACAgAAAAAg-3′; Seq. ID No. 3 and 3′b512: 5′-ACTgCTCgAgTTATgCTgACACAgCATTTC-3′; Seq. ID No. 4) derived from the sequence of WO 89/12386. Subsequent cloning into the corresponding restriction sites of the polylinker of pET24a was carried out. The resulting plasmid was designated UL5-20.

PCR Reaction Conditions

Buffer and polymerase of the company Gibco BRL were used.

DNA: 100 ng (genomic NRRL-B512F) 10 fold buffer 5 μl MgCl2 4 mM 5′ primer 50 ng 3′ primer 50 ng dNTP 1 mM of each nucleotide Pfu polymerase 0.5 units water ad 50 μl step 1 95° C. 4 minutes step 2 95° C. 1 minute step 3 55° C. 1 minute step 4 72° C. 5 minutes step 5 72° C. 10 minutes

40 repetitions were made between steps 2 and 4.

Preparation of Recombinant Dextransucrase

B21(DE3) E. coli cells containing the plasmid UL5-20 were cultured in YT medium (see above) at 37° C. up to an OD ₆₀₀=0.8. Subsequently, the cells were subjected to induction with 0.2 mM IPTG and cultured anew at 18° C. for 24 hours. After harvesting the cells by centrifugation and resuspending them in sodium phosphate buffer, pH 5.2, the cells were crushed in a French Press. The solution obtained was freed from insoluble components by centrifugation and the supernatant containing dextransucrase and referred to hereinafter as the extract was obtained.

Example 4 PCR Amplification of the Coding Region of Alternansucrase and Cloning in pET24a

The coding region of alternansucrase was amplified in a PCR reaction (see the reaction conditions below) with genomic DNA from the Leuconostoc mesenteroides strain NRRL-B1355 as a template. An Nhel restriction site was introduced at the 5′ end by means of primers A1-4 (Seq. ID No. 18), and a Sall-restriction site at the 3′ end by means of primer Al-5 (Seq. ID No. 19). A fragment of about 6200 bp was isolated.

A1-4: 5′-GGG CCC GCT AGC ATG AAA CM CM GAA ACA GT

A1-5: 5′-CCC GGG GTC GAC CTT TGT CGA ATC CTT CCC

Reaction conditions of the PCR (kit of the company Gibco BRL):

DNA 1 μl

10×buffer 5 μl

10 mM per dNTP 2 μl

50 mM MgSO₄ 2 μl

primer per 1 μl

Platinum DNA polymerase 0.2 μl

distilled water 37.8 μl

step 1 95° C., 2 minutes

step 2 95° C., 20 seconds

step 3 47° C., 20 seconds

step 4 68° C., 7 minutes (prolonged by 3 seconds per cycle)

step 5 68° C., 15 minutes

Steps 2 to 4 were repeated 35 times altogether before step 5 was carried out.

The PCR fragment obtained was purified according to standard methods, treated with the restriction endonucleases Nhel and Sall, ligated into vector pET24a (of the company Novagen) which had likewise been cut with these enzymes, and the ligation product was transformed into E. coli. After preparation of the plasmid and restriction digestion, three positive clones were selected. They were designated pAlsu-pET24a-3, pAlsu-pET24a-7 and pAlsu-pET24a-21 (see FIG. 4), respectively. All contained the sequence indicated in Seq. ID No. 20 as an insertion.

Example 5 Expression of the Recombinant Alternansucrase in E. Coli in Shake Flask Cultures and in the Fermenter

Shake Flask Culture

Plasmids pAlsu-pET24a-3, pAlsu-pET24a-7, pAlsu-pET24a-21 and pET24a were transformed into E. coli BL21 (DE3), of the company Novagen, and after initial culturing at 37° C. for 3 hours in 3 ml YT medium (Sambrook et al., Molecular Cloning, A Laboratory Manual, 2^(nd) edition (1989), Cold Spring Harbor Laboratory Press, Cold Spring Harbor, N.Y.) they were each cultured in shake flasks in 2 replicas in 50 ml Davis minimal medium (DIFCO Manual, Dehydrated Culture Media and Reagents for Microbiology, 10^(th) edition, Detroit Mich., USA (1984)) containing 0.2% glucose instead of dextrose as a carbon source at 37° C. until an OD₆₀₀ of about 0.8 was reached. After centrifugation and resuspension, one of the two replica cultures was cultured in Davis Minimal Medium (DMA) containing 1% lactose as the carbon source and inductor at 27° C. for another 16 hours. The cells of the individual cultures were harvested after centrifugation, resuspended in 50 mM sodium acetate buffer pH 5.3, and a protein extract was prepared as described in Example 2.

Fermenter

Clone pAlsu-pET24a-21 transformed in E. coli BL21(DE3) was cultured in a 2 l fermenter (Biostad B; B.Braun, Melsungen) under the following conditions:

Medium:

Fermentation medium: KH₂PO₄ 1.5 g/l, (NH₄)₂SO₄ 5.0 g/l, NaCl 0.5 g/l, Na-citrate 1.0 g/l, Fe²⁺SO₄×7 H₂O 0.075 g/l, yeast extract 0.5 g/l, tryptone 1.0 g/l, glucose 15.0 g/l, MgSO₄×7 H₂O 0.3 g/l, CaCl₂×2 H₂O 0.014 g/l, mineral salts 10 ml/l, H₃BO₃2.5 g/l, CoCl₂×6 H₂O 0.7 g/l, CuSO₄×5 H₂O 0.25 g/l, MnCl₂×4H₂O 1.6 g/l, ZnSO₄×7 H₂O 0.3 g/l, Na₂MoO₄×2 H₂O 0.15 g/l, vitamin B1 (thiamine) 0.005 g/l.

Carbon source: Glucose (1.5% (w/v)) is present in the medium, 70% (w/v) glucose solution is added.

Automatic pH control by ammonia and phosphoric acid at pH 7.0+/−0.1. A 20% concentration of pO₂ is adjusted in the medium via control by the stirrer.

Conditions:

1.5 1 of fermentation medium were inoculated with 50 ml of the preculture. The cells were first cultured at 37° C. until the glucose present was consumed. They were then cultured at the same temperature at a feeding rate of 9 g of glucose ×l⁻¹×h⁻¹ until an OD₆₀₀=40 was reached. At this time, the temperature of the culture broth was lowered to 20° C. and the amount of glucose addition was lowered to 2 g×l⁻²×h⁻¹. At a culture temperature of 20° C., the culture was subjected to induction with 0.2 mM IPTG (isopropyl-β-D-thiogalactopyranoside (Sigma)). After culturing at 20° C. for another 18 hours, the cells were harvested by centrifugation, resuspended in 50 mM sodium phosphate buffer pH 5.3 and an extract was prepared as described in Example 2.

Example 6 SDS PAGE Assay of the Activity of the Recombinant Alternansucrase, Periodic Acid Oxidation and Staining According to Schiff

Protein extracts were prepared from E. coli shake flask cultures (strain BL21 (DE3)), containing the plasmids pAlsu-pET24a-3, pAlsu-pET24a-7, pAlsu-pET24a-21 and pET24a (control), respectively. Two different extracts were each prepared from the cells transformed with the different extracts, one of said extracts being prepared before induction with IPTG and the other one being prepared after induction with IPTG at the end of culturing. The activity of these extracts of shake flask cultures (see Example 5) was detected by SDS PAGE separation of the proteins, followed by SDS removal by washing with 50 mM sodium acetate buffer pH 5.3 and incubation of the gels in 50 mM sodium acetate pH 5.3, 5% (w/v) saccharose at 37° C. for 16 hours, followed by periodic acid oxidation of the polymer formed and staining by means of acidic Schiff reagent (Miller and Robyt, Analytical Biochemistry 156, (1986), 357-363).

FIG. 5 shows that sucrase activity has not been found for either one of the extracts (preparation of the extract before and after IPTG-induction) containing the cloning vector pET24a. In the case of strains which had been transformed with the plasmids pAlsu-pET24a-3, pAlsu-pET24a-7 and pAlsu-pET24a-21, respectively, all protein extracts showed sucrase activity at the end of the induction phase (concentrated in one band).

Before induction with IPTG such activity bands were not found.

As the polymer formed in the gel can be stained according to the above-described methods by acidic Schiff reagent, it can be assumed not to be composed of pure α-1,3-linked units which would not lead to any staining.

As the gene contained in vectors pAlsu-pET24a-3, pAlsu-pET24a-7 and pAlsu-pET24a-21, respectively, was isolated from the Leuconostoc mesenteroides strain NRRL-B1355 which expresses at least one dextran sucrase apart from alternansucrase, it was not possible to determine unambiguously with this staining method whether the nucleic acid sequence contained in the plasmid actually encodes an alternansucrase. Dextrans and alternans can both be detected by this method because both polymers contain α-1,6 linkages.

Example 7 Tests for the Enzymatic Activity of Recombinantly Prepared Alternansucrases after Heat Treatment and for the Specificity of Alternansucrase

In order to prove polymerization activities, extracts from shake flask cultures were used (see Example 5). 100 μl of extract were each added to 2 ml reaction buffer (50 mM sodium acetate pH 5.3, 20% saccharose) and incubated at 37° C. for 24 hours. For comparison, an extract inactivated by a 10 minute treatment at 95° C., and an extract from E. coli BL21(DE3) containing vector pET24a were used. Polymer formation was only found in the batch that had not been inactivated, while the batch treated at 95° C. for 10 minutes and the batch with the extract from BL21 (DE3) containing pET24a did not show any polymer formation. After addition of the same volume of absolute ethanol to all batches, polymers could only be precipitated from the batch which had not been inactivated. This finding is a clear indication of the activity of alternansucrase, because the dextransucrase present in NRRL B-1355 is inactivated by a treatment at 45° C. for 30 minutes, while alternansucrase remains active under these conditions (Lopez-Munguia et al., Enzyme Microb. Technol. 15 (1993), 77-85). The enzymatic assay by a coupled enzymatic test of the glucose and fructose released and of the saccharose still contained in the reaction mixture after 24 hours, respectively, revealed that fructose was only present in the extract that was not inactivated.

For carrying out the enzymatic test either purified protein or crude protein extract is added in different dilutions to 1 ml batches containing 5% saccharose and 50 mM acetate, pH 5.5 and subjected to incubation at 37° C. After 5 minutes, 10 minutes, 15 minutes, 20 minutes, 25 minutes and 30 minutes, 10 μl each are removed from these batches and the enzymatic activity of alternansucrase is terminated by immediate heating to 95° C. Subsequently, in the coupled photometric test, the portions of fructose and glucose released by alternansucrase and the portion of used-up saccharose, respectively, are determined. For this purpose, 1 μl to 10 μl of the inactivated sample are placed into 1 ml of 50 mM imidazole buffer, pH 6.9, 2 mM MgCl₂, 1 mM ATP, 0.4 mM AND and 0.5 U/ml hexokinase. After sequential addition of about 1 u of glucose-6-phosphate dehydrogenase (from Leuconostoc mesenteroides), about 1 u of phosphoglucose isomerase and about 5 u of invertase, the alteration of adsorption at 340 nm is measured. Subsequently, the amount of fructose and glucose released and used-up saccharose, respectively, is calculated according to the Lambert-Beer law.

In control batches (inactivation of the extract by treatment with 95° C. and extract from E. coli containing pET24a) no significant release of fructose and no decrease of saccharose, respectively, was found in the reaction batch after 24 hours.

These results confirm that the specificity of the sucrase encoded by plasmids pAlsu-pET24a-3, pAlsu-pET24a-7 and pAlsu-pET24a-21, respectively, is that of a glucosyltransferase. The specificity of a fructosyl transferase, the presence of which has been described for some strains of the genus Leuconostoc is to be excluded, because otherwise glucose should have been found.

Example 8 Production of Alternan by Means of Alternansucrase Prepared in E Coli

100 ml of extract obtained by fermentation of E. coli BL21(DE3) containing plasmid pAlsu-pET24a-3 (see Example 4) were added to 900 ml of reaction buffer (50 mM sodium acetate pH 5.3, 20% saccharose) and incubated at 37° C. for 24 hours. The addition of the same amount of absolute ethanol to the reaction mixture caused the alternan formed to precipitate. After the precipitate was washed twice with 50% ethanol, it was dried by lyophilization. The yield of dried polymer based on the amount of saccharose used in the reaction was 60%.

Example 9 HPLC Analysis of Alternan and Dextran After Dextranase Digestion

100 mg of the polymer prepared in Example 7 and 100 mg of dextran T10 (Pharmacia) were each dissolved in 1 ml of water. 40 μl each of these solutions were added to 700 μl reaction buffer (50 mM potassium phosphate pH 5.7, 8 units of dextranase, ICN Biomedicals Inc. No. 190097), and incubated at 37° C. for 16 hours. 50 μl of the polymer solutions not treated with dextranase (see FIG. 6) and 50 μl of the polymer solutions treated with dextranase (FIG. 7) were analyzed by HPLC (Dionex, column PA-100, NaOH/NaOH-NaAc gradient).

In the case of dextran T10 the cleavage of the polymer into different molecules of lower molecular weights can be clearly seen. The entire high molecular weight dextran is converted by dextranase into smaller units (mostly isomaltose). By contrast, in the case of alternan, short chained oligosaccharides only appear in small amounts after dextranase incubation. Most of the alternan is not digestible by dextranase. This finding suggests that the product prepared by recombinant alternansucrase is not dextran, but alternan which is known to be hardly accessible to enzymatic digestion by dextranase (Lopez-Mungia et al., Enzyme Microb. Technol. 15, (1993), 77-85).

Example 10 In vitro Preparation of Alternan in the Absence of Dextranase

100 μl extract from shake flask cultures (see Example 5) were added to 2 ml of reaction buffer (50 mM sodium acetate, pH 5.3, 20% saccharose). 50 units of dextranase (Biomedicals Inc. No. 190097) were additionally added to another batch. Two corresponding batches which contained dextransucrase from Leuconostoc mesenteroides NRRL-B512F instead of the enzyme extract served as controls; one of these two batches had dextranase additionally admixed to it.

After precipitation with ethanol, the reaction batch with dextransucrase and dextranase did not show any polymer formation. All other batches were found to show polymer formation.

Example 11 In vitro preparation of Oligoalternan and HPLC Analysis

Oligoalternan was prepared as described in Example 2, with a protein extract in the presence of maltose and was subsequently detected (See FIG. 8) by HPLC-chromatography (see Example 2). For comparison, a portion of this batch was admixed with 50 units of dextranase (Biomedicals Inc. 190097) after preparation of oligoalternan and subsequently separation by HPLC chromatography was carried out as well (see FIG. 9). A comparison of the two chromatograms shows that not only the height of the two peaks which can be allocated to the oligoalternan (α and β-anomer) (retention time between 15.87 and 16.61 minutes) but also the height of all the other peaks, the first signs of which are already visible without dextranase, remain unchanged. This finding suggests that recombinantly prepared alternansucrase allows oligoalternan to be prepared without the simultaneous production of oligodextran. Oligodextran would be liable to digestion by dextranase, which would have to show up in a decrease of the height of the peaks in the HPLC chromatogram, if oligodextran were present.

Example 12 Methylation Analysis of Alternan

In order to further analyze the alternan produced in vitro a methylation analysis was carried out:

Permethylation

The permethylation was performed as described by Ciucanu and Kerek (Carbohydr. Res. 131 (1984), 209-218) by using NaOH/Mel in DMSO or by using a modified method according to Hakomori (Journal of Biochemistry 55 (1964 FEB), 205-208) which relies on the use of freshly prepared Li-Dimsyl/Mel (Dimsyl=methylsulfinyl carbanion) in DMSO at room temperature.

All reactions are performed under a nitrogen atmosphere. The permethylation products are isolated by extracting the excess of methyliodide by the use of dichlormethan. DMSO and salts were washed out at the end.

Degradation into Partially Methylated Sorbitacetates (Methylation Analysis)

The permethylated glucans were hydrolyzed with 2N trifluorine acetic acid at 120° C. for 1-3 hours. After cooling the acid was removed by nitrogen. Then the resulting glucans were co-distilled with a small amount of toluene, afterwards reduced by NaBD₄ in 1N ammonia and finally, acetylated by pyridine/acetanhydrid (3 h, 90° C.). The products were extracted by dichlormethan and washed with NaHCO₃. The products in the organic phase were analyzed by gas chromatography.

Analysis of the Acetylated Products

The acetylated products were analyzed by gas chromatography which was performed with a chromatograph manufactured by the Carlo-Erba company model GC 6000 Vega equipped with an on-column injector, a 25 m CPSol8CB and a FID-detector. As a carrier gas hydrogen (80 kPa) was used.

The identification and integration of the peaks was performed as described by Sweet et al. (Carbohydr. Res. 40 (1975), 217).

Results

The following main components were identified by gas chromatography:

Sorbit acetylated in position Interpretation 1, 5 Terminal Glucopyranose 1, 3, 5 3-linked Glucopyranose 1, 5, 6 6-linked Glucopyranose 1, 3, 5, 6 3,6-linked Glucopyranose

Furthermore, small amounts (rel. amount 0.2-0.4 mol %) of the following components were also found: 1, 4, 5- and 1, 3, 4, 5-sorbit and another tetraacetyl component (1,5,x,y). It is supposed that these components are due to incomplete methylation.

The following amounts were found for the above mentioned components in different experiments which were performed by changing the length of hydrolysis (indicated in bold by the number of hours) (MA=methylation analysis1; MA-b=methylation analysis 2):

Values in mol % Ac in Pos MA (1 h) MA (2 h) MA (3 h) MA-b (2 h) 1,5 10,49 10,56 9,17 12,71 1,3,5 31,69 34,70 32,95 23,12 1,4,5 0,70 0,30 0,36 0,33 1,5,6 47,02 44,17 47,23 54,62 1,3,4,5 0,27 0,22 0,25 0,31 1,5,x,y 0,19 0,32 0,36 0,24 1,3,5,6 9,64 9,73 9,68 8,67

Example 13 Construction of an Expression Cassette for Plants: Vacuolar and Plastidic Expression of an Alternansucrase

By using plasmid Alsu-pET24a as a template and the PCR primers Al-5′-1.2 and Al-3′-2.2 (see SEQ ID NO 53 and 54) we amplified the coding region of alternansucrase from Leuconostoc mesenteroides which was then cut by the restriction enzymes Sall and Pstl. Afterwards the resulting fragments were cloned into Sall and Sdal digested plasmids a) pBinAR-pat-Hyg and b) pBinAR-fnr-Hyg. The resulting plasmids were called a) pat-Alsu-Hyg (see FIG. 11) and b) fnr-Alsu-Hyg (see FIG. 12).

Note: The bacterial secretion signal peptide was removed from the cds by choice of the PCR primers.

PCR Conditions:

Buffer and polymerase from Boehringer Mannheim (Pwo Polymerase No. 1644947)

DNA 0,5 ng 10x Buffer + MgSO₄ 5 μl dNTPs (je 10 mM) 2 μl Primer Sp-AS-5′ 100 nM Primer Sp-AS-3′ 100 nM Pwo Polymerase 1,0 unit distilled water ad 50 μl Reaction conditions: Step 1 95° C. 2:30 min Step 2 95° C. 0:30 min Step 3 47° C. 0:30 min Step 4 68° C. 7:00 min (plus 3 sec per cycle) Step 5 68° C. 15:00 min 

The steps 2 to 4 were repeated 35 times in a cyclical manner.

Example 14 Northern Blot Analysis for Expression of Alternansucrase in Transgenic Plants

Leaves or tubers from potato plants transformed via agrobacteria with plasmids pat-Alsu-Hyg and fnr-Alsu-Hyg, respectively, were pulverized in a mill, type MM 200, (Retsch GmbH & Co. KG, 42781 Haan, Germany) at 30 Hz for 50 sec. RNA was extracted according to Logemann et al. (Anal. Biochem. 163 (1987), 16-20). 50 μg RNA per sample were loaded on 1 % agarose gels containing formaldehyde. After electrophoresis the RNA was transferred to nylon membranes (Hybond N, Amersham, UK) by the capillary transfer method (Sambrook et al., Molecular cloning: A laboratory manual, 2nd issue; Cold Spring Harbor Laboratory Press, NY, USA (1989)). Fixation of nucleic acids at the membrane was achieved by UV crosslinking (Stratalinker by Stratagene).

Membranes were prehybridized at 42° C. in hybridization buffer (25% (v/v) formamide, 250 mM sodium phosphate, pH 7.2, 250 mM sodiumchloride, 1 mM EDTA 7% (w/v) SDS, 25% (w/v) polyethyleneglycol 6000, 0,25 mg/ml sheared salmon sperm DNA) for 6 h. Afterwards hybridization was performed at 42° C. over night in hybridization buffer containing a radiolabelled probe in addition. The radioactive probe was prepared by using the Random Primed DNA Labelling Kit (Boehringer Mannheim, 1004760) and the approx. 4 kb Kpnl/Xhol-fragment from plasmid pAlsu-pSK according to the manufacturers manual. Membranes were washed at 50° C. once for 20 min in 3×SSC (Sambrook et al., Molecular cloning: A laboratory manual, 2nd issue; Cold Spring Harbor Laboratory Press, NY, USA (1989)) followed by washing once for 20 min in 0.5×SSC before exposing the membrane to an x-ray-film over night.

54 1 9321 DNA Leuconostoc mesenteroides CDS (678)..(6848) 1 gatcaaatag atgctaccgt tatacgagac gttaaggatt atcccaatct agtcgttttg 60 cgtaccttgt cgaaagctta tggtctggca aacctgagaa tcggctatgg cgtcatgcag 120 gaaccacttt atcaggttat gcaggccgta cgtttaccat ataatttaaa tacctatcaa 180 atcacaggtg cagtagctgc ccttagtgat caactttatc tgcaatcagt tgttgctaag 240 gtgaagtctg aacgtgaaaa atttgaacaa tttttgacga aacaccagtt taagtattat 300 caatcacaaa ccaactttct ctggattaaa gttggtgatg cgaaacgtgt tggtgaggct 360 cttctgtcag aagggtatca aattaatgac cgcctaaatg ccgaatggat tcgcattgca 420 ttaggaactg tgtctgataa tgaggggatg cagcgcattt tattgaattg ttaaaaaata 480 gctaagagag tatgttcttc tcttacctat ttttatttgt aattcctatt atttaatttt 540 gcatgacaat attaatagcg tgttacgatt ctactattta atgttaataa aattaataaa 600 tatggtatta tcttatatgg gtgatagatg caccaaatac tgtatcatgt ctggtcacat 660 gaaagggaga ataatta atg aaa caa caa gaa aca gtt acc cgt aaa aaa 710 Met Lys Gln Gln Glu Thr Val Thr Arg Lys Lys 1 5 10 ctt tat aaa tcc ggt aag gtt tgg gtt gca gca gct act gca ttt gcg 758 Leu Tyr Lys Ser Gly Lys Val Trp Val Ala Ala Ala Thr Ala Phe Ala 15 20 25 gta ttg ggg gtt tca act gta aca aca gtc cat gcg gat aca aat tcg 806 Val Leu Gly Val Ser Thr Val Thr Thr Val His Ala Asp Thr Asn Ser 30 35 40 aat gtc gct gtt aag caa ata aat aat aca gga acc aat gat tct ggc 854 Asn Val Ala Val Lys Gln Ile Asn Asn Thr Gly Thr Asn Asp Ser Gly 45 50 55 gaa aaa aag gta ccg gtt cca tca act aat aat gat agt ttg aag caa 902 Glu Lys Lys Val Pro Val Pro Ser Thr Asn Asn Asp Ser Leu Lys Gln 60 65 70 75 gga aca gat ggt ttt tgg tat gat tca gac ggc aat cgt gtc gat cag 950 Gly Thr Asp Gly Phe Trp Tyr Asp Ser Asp Gly Asn Arg Val Asp Gln 80 85 90 aag acc aat cag att ctg ctt act gcg gaa caa ctt aaa aaa aat aac 998 Lys Thr Asn Gln Ile Leu Leu Thr Ala Glu Gln Leu Lys Lys Asn Asn 95 100 105 gaa aaa aat tta tca gta atc agt gat gat aca tca aaa aaa gat gat 1046 Glu Lys Asn Leu Ser Val Ile Ser Asp Asp Thr Ser Lys Lys Asp Asp 110 115 120 gaa aat att tct aag cag acc aaa att gct aat caa caa aca gta gat 1094 Glu Asn Ile Ser Lys Gln Thr Lys Ile Ala Asn Gln Gln Thr Val Asp 125 130 135 act gct aaa ggc ctg act acc agt aat tta tct gat ccc atc act ggg 1142 Thr Ala Lys Gly Leu Thr Thr Ser Asn Leu Ser Asp Pro Ile Thr Gly 140 145 150 155 ggt cac tat gaa aat cac aat ggc tac ttt gtt tat ata gat gct tca 1190 Gly His Tyr Glu Asn His Asn Gly Tyr Phe Val Tyr Ile Asp Ala Ser 160 165 170 gga aaa caa gta aca ggt ttg caa aat att gat ggt aat tta caa tat 1238 Gly Lys Gln Val Thr Gly Leu Gln Asn Ile Asp Gly Asn Leu Gln Tyr 175 180 185 ttt gat gac aat gga tat caa gtc aag gga tcc ttc cga gat gtc aac 1286 Phe Asp Asp Asn Gly Tyr Gln Val Lys Gly Ser Phe Arg Asp Val Asn 190 195 200 ggc aag cat atc tat ttt gat tca gta aca ggg aaa gct agt tca aat 1334 Gly Lys His Ile Tyr Phe Asp Ser Val Thr Gly Lys Ala Ser Ser Asn 205 210 215 gtt gat att gtt aac ggt aaa gct caa gga tat gat gcg caa ggc aac 1382 Val Asp Ile Val Asn Gly Lys Ala Gln Gly Tyr Asp Ala Gln Gly Asn 220 225 230 235 caa tta aag aaa agt tat gtc gcc gat agt tct ggg caa act tac tat 1430 Gln Leu Lys Lys Ser Tyr Val Ala Asp Ser Ser Gly Gln Thr Tyr Tyr 240 245 250 ttt gat ggt aat ggc caa ccg tta atc ggc ttg caa aca att gat ggg 1478 Phe Asp Gly Asn Gly Gln Pro Leu Ile Gly Leu Gln Thr Ile Asp Gly 255 260 265 aac cta caa tat ttt aac caa caa ggg gtt caa ata aag ggt ggt ttc 1526 Asn Leu Gln Tyr Phe Asn Gln Gln Gly Val Gln Ile Lys Gly Gly Phe 270 275 280 caa gat gtt aac aat aaa cgt att tat ttt gca cca aac aca ggt aat 1574 Gln Asp Val Asn Asn Lys Arg Ile Tyr Phe Ala Pro Asn Thr Gly Asn 285 290 295 gcc gtt gcc aat act gaa ata att aac ggt aaa tta cag ggg cgt gac 1622 Ala Val Ala Asn Thr Glu Ile Ile Asn Gly Lys Leu Gln Gly Arg Asp 300 305 310 315 gca aat ggt aac cag gta aag aat gca ttt agt aaa gat gtt gca gga 1670 Ala Asn Gly Asn Gln Val Lys Asn Ala Phe Ser Lys Asp Val Ala Gly 320 325 330 aat aca ttt tat ttt gac gca aac ggt gtg atg tta aca ggg ttg caa 1718 Asn Thr Phe Tyr Phe Asp Ala Asn Gly Val Met Leu Thr Gly Leu Gln 335 340 345 act att tca gga aag aca tat tat ctt gat gaa caa gga cac ctg aga 1766 Thr Ile Ser Gly Lys Thr Tyr Tyr Leu Asp Glu Gln Gly His Leu Arg 350 355 360 aaa aat tac gcg gga aca ttc aat aat cag ttt atg tac ttc gat gct 1814 Lys Asn Tyr Ala Gly Thr Phe Asn Asn Gln Phe Met Tyr Phe Asp Ala 365 370 375 gat aca ggt gcg ggt aaa aca gcg att gaa tat caa ttt gat caa gga 1862 Asp Thr Gly Ala Gly Lys Thr Ala Ile Glu Tyr Gln Phe Asp Gln Gly 380 385 390 395 ttg gta tca caa agt aat gaa aat act cct cac aat gcc gca aag tct 1910 Leu Val Ser Gln Ser Asn Glu Asn Thr Pro His Asn Ala Ala Lys Ser 400 405 410 tat gat aaa agt agt ttt gaa aat gtt gat ggt tac tta aca gca gat 1958 Tyr Asp Lys Ser Ser Phe Glu Asn Val Asp Gly Tyr Leu Thr Ala Asp 415 420 425 aca tgg tat cgt cca acc gat att tta aaa aat gga gat act tgg acg 2006 Thr Trp Tyr Arg Pro Thr Asp Ile Leu Lys Asn Gly Asp Thr Trp Thr 430 435 440 gca tct acc gaa act gat atg cgt ccg ctt tta atg aca tgg tgg cct 2054 Ala Ser Thr Glu Thr Asp Met Arg Pro Leu Leu Met Thr Trp Trp Pro 445 450 455 gac aaa caa aca caa gca aat tac ttg aat ttt atg tct agt aaa gga 2102 Asp Lys Gln Thr Gln Ala Asn Tyr Leu Asn Phe Met Ser Ser Lys Gly 460 465 470 475 ctt ggt ata acg acc act tat aca gca gct acg tca caa aaa aca cta 2150 Leu Gly Ile Thr Thr Thr Tyr Thr Ala Ala Thr Ser Gln Lys Thr Leu 480 485 490 aat gac gca gcc ttt gtt att caa aca gca att gaa caa caa ata tct 2198 Asn Asp Ala Ala Phe Val Ile Gln Thr Ala Ile Glu Gln Gln Ile Ser 495 500 505 ttg aaa aaa agt act gag tgg tta cgt gat gca att gat agt ttt gtg 2246 Leu Lys Lys Ser Thr Glu Trp Leu Arg Asp Ala Ile Asp Ser Phe Val 510 515 520 aag acg caa gct aat tgg aat aag caa aca gaa gat gaa gct ttc gat 2294 Lys Thr Gln Ala Asn Trp Asn Lys Gln Thr Glu Asp Glu Ala Phe Asp 525 530 535 ggt ttg cag tgg ctt caa ggg gga ttc cta gct tat caa gat gat tca 2342 Gly Leu Gln Trp Leu Gln Gly Gly Phe Leu Ala Tyr Gln Asp Asp Ser 540 545 550 555 cat cgg acg ccg aat act gat tca gga aat aac aga aaa cta gga cgt 2390 His Arg Thr Pro Asn Thr Asp Ser Gly Asn Asn Arg Lys Leu Gly Arg 560 565 570 caa cca att aat atc gat ggt tcg aaa gat aca act gat ggt aaa ggc 2438 Gln Pro Ile Asn Ile Asp Gly Ser Lys Asp Thr Thr Asp Gly Lys Gly 575 580 585 tct gaa ttc tta tta gct aac gat att gac aac tca aat ccg att gtt 2486 Ser Glu Phe Leu Leu Ala Asn Asp Ile Asp Asn Ser Asn Pro Ile Val 590 595 600 caa gct gag caa tta aac tgg cta cac tat tta atg aat ttt ggt agt 2534 Gln Ala Glu Gln Leu Asn Trp Leu His Tyr Leu Met Asn Phe Gly Ser 605 610 615 att aca ggt aat aat gac aat gcg aat ttt gat ggc att cgt gta gat 2582 Ile Thr Gly Asn Asn Asp Asn Ala Asn Phe Asp Gly Ile Arg Val Asp 620 625 630 635 gct gtt gat aat gtt gat gct gat tta cta aaa ata gct ggc gat tat 2630 Ala Val Asp Asn Val Asp Ala Asp Leu Leu Lys Ile Ala Gly Asp Tyr 640 645 650 ttt aaa gct cta tat ggt aca gat aaa agc gac gcc aat gcc aat aag 2678 Phe Lys Ala Leu Tyr Gly Thr Asp Lys Ser Asp Ala Asn Ala Asn Lys 655 660 665 cat ttg tct att tta gaa gac tgg aac ggt aaa gat cct cag tat gtt 2726 His Leu Ser Ile Leu Glu Asp Trp Asn Gly Lys Asp Pro Gln Tyr Val 670 675 680 aat caa cag ggc aat gcg caa tta aca atg gat tac aca gtt act tca 2774 Asn Gln Gln Gly Asn Ala Gln Leu Thr Met Asp Tyr Thr Val Thr Ser 685 690 695 cag ttt ggc aat tct cta aca cat ggc gcc aac aac agg agt aac atg 2822 Gln Phe Gly Asn Ser Leu Thr His Gly Ala Asn Asn Arg Ser Asn Met 700 705 710 715 tgg tat ttc tta gat act ggc tat tat ctt aat gga gat ctt aat aag 2870 Trp Tyr Phe Leu Asp Thr Gly Tyr Tyr Leu Asn Gly Asp Leu Asn Lys 720 725 730 aag ata gta gat aag aac cgt cca aat tct ggc act ttg gtt aac aga 2918 Lys Ile Val Asp Lys Asn Arg Pro Asn Ser Gly Thr Leu Val Asn Arg 735 740 745 att gct aat tca ggt gat aca aaa gtt att cca aat tat agt ttt gtt 2966 Ile Ala Asn Ser Gly Asp Thr Lys Val Ile Pro Asn Tyr Ser Phe Val 750 755 760 aga gca cat gat tac gat gct caa gat cca att aga aaa gcc atg att 3014 Arg Ala His Asp Tyr Asp Ala Gln Asp Pro Ile Arg Lys Ala Met Ile 765 770 775 gat cat ggt att att aaa aac atg cag gat act ttc act ttt gac caa 3062 Asp His Gly Ile Ile Lys Asn Met Gln Asp Thr Phe Thr Phe Asp Gln 780 785 790 795 ctg gct cag gga atg gaa ttc tac tat aaa gat caa gag aat ccg tct 3110 Leu Ala Gln Gly Met Glu Phe Tyr Tyr Lys Asp Gln Glu Asn Pro Ser 800 805 810 ggt ttc aaa aag tat aac gat tat aac tta cct agt gct tat gca atg 3158 Gly Phe Lys Lys Tyr Asn Asp Tyr Asn Leu Pro Ser Ala Tyr Ala Met 815 820 825 ttg ttg act aat aag gat act gta cct cgt gtc tat tat gga gat atg 3206 Leu Leu Thr Asn Lys Asp Thr Val Pro Arg Val Tyr Tyr Gly Asp Met 830 835 840 tac ctc gaa ggc ggg caa tat atg gaa aaa ggg acg att tac aat cct 3254 Tyr Leu Glu Gly Gly Gln Tyr Met Glu Lys Gly Thr Ile Tyr Asn Pro 845 850 855 gtc att tca gcg ttg ctc aaa gct aga ata aaa tat gtt tct ggt ggg 3302 Val Ile Ser Ala Leu Leu Lys Ala Arg Ile Lys Tyr Val Ser Gly Gly 860 865 870 875 caa aca atg gct acc gat agt tct gga aaa gac ctt aaa gat ggc gaa 3350 Gln Thr Met Ala Thr Asp Ser Ser Gly Lys Asp Leu Lys Asp Gly Glu 880 885 890 act gat ttg tta aca agt gtt cga ttt ggt aaa gga att atg aca tca 3398 Thr Asp Leu Leu Thr Ser Val Arg Phe Gly Lys Gly Ile Met Thr Ser 895 900 905 gat caa acc aca aca caa gac aat agc caa gat tat aaa aat caa ggc 3446 Asp Gln Thr Thr Thr Gln Asp Asn Ser Gln Asp Tyr Lys Asn Gln Gly 910 915 920 atc ggt gtc att gtt ggt aat aac cct gac ctt aag ttg aac aat gat 3494 Ile Gly Val Ile Val Gly Asn Asn Pro Asp Leu Lys Leu Asn Asn Asp 925 930 935 aag acc att acc ttg cat atg gga aag gcg cat aag aat caa ctt tac 3542 Lys Thr Ile Thr Leu His Met Gly Lys Ala His Lys Asn Gln Leu Tyr 940 945 950 955 cgt gcc tta gta tta tca aat gac tca gga att gat gtt tat gat agt 3590 Arg Ala Leu Val Leu Ser Asn Asp Ser Gly Ile Asp Val Tyr Asp Ser 960 965 970 gat gat aaa gca cca act ttg aga aca aat gac aac ggt gac ttg att 3638 Asp Asp Lys Ala Pro Thr Leu Arg Thr Asn Asp Asn Gly Asp Leu Ile 975 980 985 ttc cat aag aca aat acg ttt gtg aag caa gat gga act att ata aat 3686 Phe His Lys Thr Asn Thr Phe Val Lys Gln Asp Gly Thr Ile Ile Asn 990 995 1000 tac gaa atg aag gga tca tta aat gct tta att tca ggt tat tta ggt 3734 Tyr Glu Met Lys Gly Ser Leu Asn Ala Leu Ile Ser Gly Tyr Leu Gly 1005 1010 1015 gtc tgg gtg cca gtt gga gct agt gat tca caa gat gct cgt aca gtg 3782 Val Trp Val Pro Val Gly Ala Ser Asp Ser Gln Asp Ala Arg Thr Val 1020 1025 1030 1035 gca act gag tca tca tca agt aat gat ggt tct gta ttc cat tca aat 3830 Ala Thr Glu Ser Ser Ser Ser Asn Asp Gly Ser Val Phe His Ser Asn 1040 1045 1050 gct gca tta gat tct aat gtt ata tat gaa ggc ttt tca aac ttt caa 3878 Ala Ala Leu Asp Ser Asn Val Ile Tyr Glu Gly Phe Ser Asn Phe Gln 1055 1060 1065 gcg atg ccg act tct cct gag caa agt aca aat gtt gtt att gca aca 3926 Ala Met Pro Thr Ser Pro Glu Gln Ser Thr Asn Val Val Ile Ala Thr 1070 1075 1080 aag gct aac tta ttt aaa gaa tta ggt att act agt ttt gag tta gca 3974 Lys Ala Asn Leu Phe Lys Glu Leu Gly Ile Thr Ser Phe Glu Leu Ala 1085 1090 1095 cct caa tat agg tct agt ggt gac act aat tac ggt ggc atg tca ttc 4022 Pro Gln Tyr Arg Ser Ser Gly Asp Thr Asn Tyr Gly Gly Met Ser Phe 1100 1105 1110 1115 tta gat tct ttc tta aat aat ggt tat gca ttt acc gat aga tat gat 4070 Leu Asp Ser Phe Leu Asn Asn Gly Tyr Ala Phe Thr Asp Arg Tyr Asp 1120 1125 1130 tta ggc ttt aac aaa gca gac ggg aat cct aac cca aca aag tat gga 4118 Leu Gly Phe Asn Lys Ala Asp Gly Asn Pro Asn Pro Thr Lys Tyr Gly 1135 1140 1145 aca gat caa gat tta cgt aat gca ata gag gca tta cac aaa aac ggc 4166 Thr Asp Gln Asp Leu Arg Asn Ala Ile Glu Ala Leu His Lys Asn Gly 1150 1155 1160 atg cag gct ata gct gat tgg gtt cct gac caa ata tat gct tta cca 4214 Met Gln Ala Ile Ala Asp Trp Val Pro Asp Gln Ile Tyr Ala Leu Pro 1165 1170 1175 gga aag gaa gtt gtt acc gct act aga gta gac gaa cgg gga aat caa 4262 Gly Lys Glu Val Val Thr Ala Thr Arg Val Asp Glu Arg Gly Asn Gln 1180 1185 1190 1195 cta aaa gac aca gat ttt gtc aac tta ctc tat gtt gct aat act aaa 4310 Leu Lys Asp Thr Asp Phe Val Asn Leu Leu Tyr Val Ala Asn Thr Lys 1200 1205 1210 agt agt ggt gtg gat tat cag gca aag tat ggc ggc gaa ttt tta gat 4358 Ser Ser Gly Val Asp Tyr Gln Ala Lys Tyr Gly Gly Glu Phe Leu Asp 1215 1220 1225 aaa tta aga gaa gag tac cca tcg tta ttc aaa cag aac caa gta tcg 4406 Lys Leu Arg Glu Glu Tyr Pro Ser Leu Phe Lys Gln Asn Gln Val Ser 1230 1235 1240 aca ggt cag cca att gat gct tct aca aaa att aag caa tgg tca gct 4454 Thr Gly Gln Pro Ile Asp Ala Ser Thr Lys Ile Lys Gln Trp Ser Ala 1245 1250 1255 aaa tat atg aat ggg acc aat att tta cat cga ggt gct tat tat gtt 4502 Lys Tyr Met Asn Gly Thr Asn Ile Leu His Arg Gly Ala Tyr Tyr Val 1260 1265 1270 1275 ttg aaa gac tgg gct act aac cag tat ttt aac att gca aaa acg aat 4550 Leu Lys Asp Trp Ala Thr Asn Gln Tyr Phe Asn Ile Ala Lys Thr Asn 1280 1285 1290 gaa gta ttt ttg cca cta cag ttg cag aat aaa gat gcg caa act ggt 4598 Glu Val Phe Leu Pro Leu Gln Leu Gln Asn Lys Asp Ala Gln Thr Gly 1295 1300 1305 ttc att agt gat gcc tcc ggt gta aaa tat tac tca att agt ggt tat 4646 Phe Ile Ser Asp Ala Ser Gly Val Lys Tyr Tyr Ser Ile Ser Gly Tyr 1310 1315 1320 caa gca aaa gat act ttt att gaa gat ggt aat ggg aat tgg tat tac 4694 Gln Ala Lys Asp Thr Phe Ile Glu Asp Gly Asn Gly Asn Trp Tyr Tyr 1325 1330 1335 ttt gat aaa gat ggt tac atg gtg cgt tcg cag caa gga gaa aat cct 4742 Phe Asp Lys Asp Gly Tyr Met Val Arg Ser Gln Gln Gly Glu Asn Pro 1340 1345 1350 1355 ata aga aca gtc gaa act agt gtc aac aca cga aac ggt aat tat tac 4790 Ile Arg Thr Val Glu Thr Ser Val Asn Thr Arg Asn Gly Asn Tyr Tyr 1360 1365 1370 ttt atg cca aat ggt gtc gag ttg cgc aaa ggc ttt gga acg gat aat 4838 Phe Met Pro Asn Gly Val Glu Leu Arg Lys Gly Phe Gly Thr Asp Asn 1375 1380 1385 agt ggt aat gtc tat tat ttt gat gat caa ggt aag atg gtg aga gat 4886 Ser Gly Asn Val Tyr Tyr Phe Asp Asp Gln Gly Lys Met Val Arg Asp 1390 1395 1400 aaa tac att aac gat gat gct aat aat ttt tat cac tta aat gtt gat 4934 Lys Tyr Ile Asn Asp Asp Ala Asn Asn Phe Tyr His Leu Asn Val Asp 1405 1410 1415 ggg act atg tct cga gga cta ttt aaa ttt gat tct gat act cta cag 4982 Gly Thr Met Ser Arg Gly Leu Phe Lys Phe Asp Ser Asp Thr Leu Gln 1420 1425 1430 1435 tat ttt gct agt aat ggt gtc caa ata aaa gat agt tat gcg aag gat 5030 Tyr Phe Ala Ser Asn Gly Val Gln Ile Lys Asp Ser Tyr Ala Lys Asp 1440 1445 1450 agt aaa ggc aat aaa tat tat ttt gac tca gct aca gga aat aac gat 5078 Ser Lys Gly Asn Lys Tyr Tyr Phe Asp Ser Ala Thr Gly Asn Asn Asp 1455 1460 1465 act ggg aaa gcc caa act tgg gat ggt aat ggc tac tat att act att 5126 Thr Gly Lys Ala Gln Thr Trp Asp Gly Asn Gly Tyr Tyr Ile Thr Ile 1470 1475 1480 gat tct gat gcg aac aat aca att ggg gtt aac aca gac tac act gcc 5174 Asp Ser Asp Ala Asn Asn Thr Ile Gly Val Asn Thr Asp Tyr Thr Ala 1485 1490 1495 tac atc act agc tcg ctg cgc gaa gat ggc tta ttt gct aac gca cct 5222 Tyr Ile Thr Ser Ser Leu Arg Glu Asp Gly Leu Phe Ala Asn Ala Pro 1500 1505 1510 1515 tac ggt gtt gta aca aaa gac caa aat ggt aac gat ctt aag tgg cag 5270 Tyr Gly Val Val Thr Lys Asp Gln Asn Gly Asn Asp Leu Lys Trp Gln 1520 1525 1530 tat att aac cat acg aaa cag tac gaa ggg caa caa gtg caa gtc acg 5318 Tyr Ile Asn His Thr Lys Gln Tyr Glu Gly Gln Gln Val Gln Val Thr 1535 1540 1545 cgt caa tac aca gac agt aag gga gtc agc tgg aac tta att acc ttt 5366 Arg Gln Tyr Thr Asp Ser Lys Gly Val Ser Trp Asn Leu Ile Thr Phe 1550 1555 1560 gct ggt ggt gat tta caa gga caa agg ctt tgg gtg gat agt cgt gcg 5414 Ala Gly Gly Asp Leu Gln Gly Gln Arg Leu Trp Val Asp Ser Arg Ala 1565 1570 1575 tta act atg aca cca ttt aaa acg atg aac caa ata agc ttc att agt 5462 Leu Thr Met Thr Pro Phe Lys Thr Met Asn Gln Ile Ser Phe Ile Ser 1580 1585 1590 1595 tat gct aac cgc aat gat ggg ttg ttt ttg aat gcg cca tac caa gtc 5510 Tyr Ala Asn Arg Asn Asp Gly Leu Phe Leu Asn Ala Pro Tyr Gln Val 1600 1605 1610 aag ggg tat caa tta gct ggg atg tcc aac caa tac aag ggc caa caa 5558 Lys Gly Tyr Gln Leu Ala Gly Met Ser Asn Gln Tyr Lys Gly Gln Gln 1615 1620 1625 gtg acc att gct ggg gtg gcg aac gtt tct gga aaa gac tgg agt ctg 5606 Val Thr Ile Ala Gly Val Ala Asn Val Ser Gly Lys Asp Trp Ser Leu 1630 1635 1640 att agt ttt aat ggg aca cag tac tgg att gat agt cag gca ttg aat 5654 Ile Ser Phe Asn Gly Thr Gln Tyr Trp Ile Asp Ser Gln Ala Leu Asn 1645 1650 1655 acc aat ttc aca cat gac atg aac caa aag gtc ttt gtc aat aca act 5702 Thr Asn Phe Thr His Asp Met Asn Gln Lys Val Phe Val Asn Thr Thr 1660 1665 1670 1675 agt aat ctt gat ggg tta ttc tta aat gcg cca tac cgt caa ccg ggt 5750 Ser Asn Leu Asp Gly Leu Phe Leu Asn Ala Pro Tyr Arg Gln Pro Gly 1680 1685 1690 tat aag tta gcc ggt ttg gct aaa aat tac aac aac caa acg gtt act 5798 Tyr Lys Leu Ala Gly Leu Ala Lys Asn Tyr Asn Asn Gln Thr Val Thr 1695 1700 1705 gtt agt caa cag tac ttt gat gat caa ggc acg gtc tgg agt cag gtt 5846 Val Ser Gln Gln Tyr Phe Asp Asp Gln Gly Thr Val Trp Ser Gln Val 1710 1715 1720 gtc ctt ggg ggt cag acg gtc tgg gtt gat aac cat gca ttg gca cag 5894 Val Leu Gly Gly Gln Thr Val Trp Val Asp Asn His Ala Leu Ala Gln 1725 1730 1735 atg caa gtt agt gat aca gac caa cag ctc tat gtg aat agc aat ggt 5942 Met Gln Val Ser Asp Thr Asp Gln Gln Leu Tyr Val Asn Ser Asn Gly 1740 1745 1750 1755 cgg aat gat ggg tta ttc ttg aat gcg cca tat cgt ggt caa ggg tca 5990 Arg Asn Asp Gly Leu Phe Leu Asn Ala Pro Tyr Arg Gly Gln Gly Ser 1760 1765 1770 caa ctg ata ggc atg acg gca gat tat aat ggg caa cat gta caa gtg 6038 Gln Leu Ile Gly Met Thr Ala Asp Tyr Asn Gly Gln His Val Gln Val 1775 1780 1785 acc aag caa ggg caa gat gcc tat ggt gca caa tgg cgt ctt att acg 6086 Thr Lys Gln Gly Gln Asp Ala Tyr Gly Ala Gln Trp Arg Leu Ile Thr 1790 1795 1800 cta aat aat caa cag gtc tgg gtt gat agt cgc gct ttg agc aca aca 6134 Leu Asn Asn Gln Gln Val Trp Val Asp Ser Arg Ala Leu Ser Thr Thr 1805 1810 1815 atc atg caa gcc atg aat gat aat atg tat gta aat agc agc caa cgg 6182 Ile Met Gln Ala Met Asn Asp Asn Met Tyr Val Asn Ser Ser Gln Arg 1820 1825 1830 1835 aca gat ggc ttg tgg tta aac gca cct tat acg atg agt ggg gct aaa 6230 Thr Asp Gly Leu Trp Leu Asn Ala Pro Tyr Thr Met Ser Gly Ala Lys 1840 1845 1850 tgg gct ggt gat aca cgt tca gct aat ggg cgc tat gtc cat att tca 6278 Trp Ala Gly Asp Thr Arg Ser Ala Asn Gly Arg Tyr Val His Ile Ser 1855 1860 1865 aaa gct tat tca aac gaa gtc ggc aat aca tat tac ttg acg aat ttg 6326 Lys Ala Tyr Ser Asn Glu Val Gly Asn Thr Tyr Tyr Leu Thr Asn Leu 1870 1875 1880 aat ggt caa agc aca tgg att gac aag cgg gcg ttt act gtg acc ttc 6374 Asn Gly Gln Ser Thr Trp Ile Asp Lys Arg Ala Phe Thr Val Thr Phe 1885 1890 1895 gat cag gtg gtg gca tta aat gca acg att gtg gca cgc caa cga cca 6422 Asp Gln Val Val Ala Leu Asn Ala Thr Ile Val Ala Arg Gln Arg Pro 1900 1905 1910 1915 gat ggg atg ttt aag aca gca cca tat ggt gaa gcg ggg gcg cag ttt 6470 Asp Gly Met Phe Lys Thr Ala Pro Tyr Gly Glu Ala Gly Ala Gln Phe 1920 1925 1930 gtc gat tat gtg aca aac tat aac cag caa acc gtg cca gta aca aag 6518 Val Asp Tyr Val Thr Asn Tyr Asn Gln Gln Thr Val Pro Val Thr Lys 1935 1940 1945 caa cat tca gat gct cag ggg aat caa tgg tac tta gcg aca gtg aat 6566 Gln His Ser Asp Ala Gln Gly Asn Gln Trp Tyr Leu Ala Thr Val Asn 1950 1955 1960 ggg aca caa tac tgg att gat caa cgg tca ttt tca cca gta gta acg 6614 Gly Thr Gln Tyr Trp Ile Asp Gln Arg Ser Phe Ser Pro Val Val Thr 1965 1970 1975 aag gtg gtt gat tat caa gct aag att gtg cca cgg aca aca cgt gat 6662 Lys Val Val Asp Tyr Gln Ala Lys Ile Val Pro Arg Thr Thr Arg Asp 1980 1985 1990 1995 ggt gtg ttt agt ggc gca ccc tat ggg gaa gtg aat gct aag cta gtt 6710 Gly Val Phe Ser Gly Ala Pro Tyr Gly Glu Val Asn Ala Lys Leu Val 2000 2005 2010 aac atg gca act gcg tat caa aat caa gtt gtc cat gcg aca ggg gaa 6758 Asn Met Ala Thr Ala Tyr Gln Asn Gln Val Val His Ala Thr Gly Glu 2015 2020 2025 tat acg aat gct tca ggg atc aca tgg agt cag ttc gcg tta agc ggg 6806 Tyr Thr Asn Ala Ser Gly Ile Thr Trp Ser Gln Phe Ala Leu Ser Gly 2030 2035 2040 caa gaa gac aag cta tgg att gat aag cgt gct ttg caa gct 6848 Gln Glu Asp Lys Leu Trp Ile Asp Lys Arg Ala Leu Gln Ala 2045 2050 2055 taagggaagg attcgacaaa ggagggtaac attatcagcg gatggtgtta tcctcctttc 6908 ctgtactcag tatttcccaa ataattgaga cagtttcatg acaaatcaac aaaactagtg 6968 tcaatgcctc ggttatgggg taaactacta ttagttaaag ggttgttgca taataatatc 7028 acattcaata tattatgtat ttttatctga ttatgtgatt ttttgagatt tggagcgaaa 7088 atgaataaag taataattaa taaaagtttc tgtgttttgg taatgagttt gttgtcgata 7148 tttctattct cattaagagt agacgctcgt tccaatagtg gctacaatca aatatctttt 7208 aatcaacatg aaattgctta tgcgcctttt agtcaagtac cttggtatgc aactgtgaat 7268 gtcggaatgt ctgcagacaa aaataatatc tatacagcta ttgatatggg gccatagtat 7328 caaggaactt ctttttttcc gtggtggtat caacatgata attatgatta tcatgatggt 7388 tatcaacttg cgattgacaa tcaatcgctt ttcatagaaa tggttgatac aggaaggtcg 7448 tcgtttgatg ttattgagtt gtatacaggt aaaaaagttg gttatggaaa attcacagcc 7508 tataactata acaagacttc atggcagttt caaatatctt taaaggcgat aaagaaaatt 7568 ttaaataata acatatcaga aaatgcgaca attagtttgt acaatggtta tctattcaaa 7628 caagccgaaa gtatcacgta tgctggttca ccaacagggc catggttact tgccggtatt 7688 ggtttggttt ttgctggtgg gggctattac ctgcaaaatc agcgccgaaa aacgattacg 7748 gcatcatcaa caaacgaggt aacccatgct taataatgct gttattattg gtctaattat 7808 tatttgggtc tatgtattat ctgttctgaa gcgtgctaaa acggatgcgt tttatttttt 7868 ggctggcagc gcaggcttgt tcgtcattct tcttttatgg agtaaacctt atggtgtttg 7928 gttgttttcg accattctca cttggtcggc cggggttgtt ggtcatctca ctggcttatt 7988 tgatactttc tatgcgtcac atgttattca ggttgtggcg aatcatcata ccagcatttt 8048 attggttgat tatgaatgtt caggcattat tgaaacaacg gcattttggg gattaattgc 8108 cttttatcct gtgtatgatg cacaaaagcg gttaatgttg gcgcttattg gggcattatg 8168 gtttttcctt gcaaatacgt tacgactatc ttttgttgca gttgtaattt attattttgg 8228 cgatggcgct ttttatgttg ctcattcaat tatcggacgc ctgttgttct attcaattgt 8288 aatcttgctt tattatctag tcttcataaa ggggcaactt gttaatcaaa tgctcaaaaa 8348 acagggataa actatgtcat tttatttaca tcaatttact tatcagttag gtttttggtt 8408 cacttggttg ctcattccgt ttgttgtgga aattttccca gctattattt caatctagtt 8468 ttgataaaaa catcaaaaaa gcatcaagtg atgcaagaac cattgaaatt accaatggta 8528 tctattgtat tacctatata taattcagga caaacattat accagtgtat tcagtcgatt 8588 agtcaatcaa cctatccaaa acaattaatc caaattattg ccgtgaataa tcaaagcact 8648 gataacagtt ttacagtgtt taatcaggct caagctgatt tcccaatact tagaatgcag 8708 tggatgaaca cagatcaagg taaagcgcgt gcactaaatg ctgctattta taatagtatg 8768 gggcaatata ttattaattt ggatactgat ggttggttag aacccaatgc cttaaaacgg 8828 tttgtgcttt attttgaaaa tcactcagaa attgatgtag caactggtac gattctgaca 8888 caaaaaaaaa tgattcaaaa aacgcaaagt aaatggctta aattgctaca gttaaacgaa 8948 tattttgagt atgcacaatc attcttatca ggccgtagta ttgaaaaccg tggtaatcgt 9008 ttgttcacaa tgtcaggtgc attttcagcg tttagacgtg atgtattagt tcagacattt 9068 atgtataatg ttgacacggt tggtgaagat actgatatga catttcaact gcgattccgc 9128 ctaggcaagc gtattggttt ctgtgatgat gccatgtttt atgttgaacc aatatcaggt 9188 tatagtgaac tttatttaca acggcagcgt tggcagcgtg ggcaaattga agtcgcacaa 9248 aatttcatgc agaataagtt gagtgtccgt cagattttta ctaactttat gattagtcga 9308 ttaatgattg atc 9321 2 2057 PRT Leuconostoc mesenteroides 2 Met Lys Gln Gln Glu Thr Val Thr Arg Lys Lys Leu Tyr Lys Ser Gly 1 5 10 15 Lys Val Trp Val Ala Ala Ala Thr Ala Phe Ala Val Leu Gly Val Ser 20 25 30 Thr Val Thr Thr Val His Ala Asp Thr Asn Ser Asn Val Ala Val Lys 35 40 45 Gln Ile Asn Asn Thr Gly Thr Asn Asp Ser Gly Glu Lys Lys Val Pro 50 55 60 Val Pro Ser Thr Asn Asn Asp Ser Leu Lys Gln Gly Thr Asp Gly Phe 65 70 75 80 Trp Tyr Asp Ser Asp Gly Asn Arg Val Asp Gln Lys Thr Asn Gln Ile 85 90 95 Leu Leu Thr Ala Glu Gln Leu Lys Lys Asn Asn Glu Lys Asn Leu Ser 100 105 110 Val Ile Ser Asp Asp Thr Ser Lys Lys Asp Asp Glu Asn Ile Ser Lys 115 120 125 Gln Thr Lys Ile Ala Asn Gln Gln Thr Val Asp Thr Ala Lys Gly Leu 130 135 140 Thr Thr Ser Asn Leu Ser Asp Pro Ile Thr Gly Gly His Tyr Glu Asn 145 150 155 160 His Asn Gly Tyr Phe Val Tyr Ile Asp Ala Ser Gly Lys Gln Val Thr 165 170 175 Gly Leu Gln Asn Ile Asp Gly Asn Leu Gln Tyr Phe Asp Asp Asn Gly 180 185 190 Tyr Gln Val Lys Gly Ser Phe Arg Asp Val Asn Gly Lys His Ile Tyr 195 200 205 Phe Asp Ser Val Thr Gly Lys Ala Ser Ser Asn Val Asp Ile Val Asn 210 215 220 Gly Lys Ala Gln Gly Tyr Asp Ala Gln Gly Asn Gln Leu Lys Lys Ser 225 230 235 240 Tyr Val Ala Asp Ser Ser Gly Gln Thr Tyr Tyr Phe Asp Gly Asn Gly 245 250 255 Gln Pro Leu Ile Gly Leu Gln Thr Ile Asp Gly Asn Leu Gln Tyr Phe 260 265 270 Asn Gln Gln Gly Val Gln Ile Lys Gly Gly Phe Gln Asp Val Asn Asn 275 280 285 Lys Arg Ile Tyr Phe Ala Pro Asn Thr Gly Asn Ala Val Ala Asn Thr 290 295 300 Glu Ile Ile Asn Gly Lys Leu Gln Gly Arg Asp Ala Asn Gly Asn Gln 305 310 315 320 Val Lys Asn Ala Phe Ser Lys Asp Val Ala Gly Asn Thr Phe Tyr Phe 325 330 335 Asp Ala Asn Gly Val Met Leu Thr Gly Leu Gln Thr Ile Ser Gly Lys 340 345 350 Thr Tyr Tyr Leu Asp Glu Gln Gly His Leu Arg Lys Asn Tyr Ala Gly 355 360 365 Thr Phe Asn Asn Gln Phe Met Tyr Phe Asp Ala Asp Thr Gly Ala Gly 370 375 380 Lys Thr Ala Ile Glu Tyr Gln Phe Asp Gln Gly Leu Val Ser Gln Ser 385 390 395 400 Asn Glu Asn Thr Pro His Asn Ala Ala Lys Ser Tyr Asp Lys Ser Ser 405 410 415 Phe Glu Asn Val Asp Gly Tyr Leu Thr Ala Asp Thr Trp Tyr Arg Pro 420 425 430 Thr Asp Ile Leu Lys Asn Gly Asp Thr Trp Thr Ala Ser Thr Glu Thr 435 440 445 Asp Met Arg Pro Leu Leu Met Thr Trp Trp Pro Asp Lys Gln Thr Gln 450 455 460 Ala Asn Tyr Leu Asn Phe Met Ser Ser Lys Gly Leu Gly Ile Thr Thr 465 470 475 480 Thr Tyr Thr Ala Ala Thr Ser Gln Lys Thr Leu Asn Asp Ala Ala Phe 485 490 495 Val Ile Gln Thr Ala Ile Glu Gln Gln Ile Ser Leu Lys Lys Ser Thr 500 505 510 Glu Trp Leu Arg Asp Ala Ile Asp Ser Phe Val Lys Thr Gln Ala Asn 515 520 525 Trp Asn Lys Gln Thr Glu Asp Glu Ala Phe Asp Gly Leu Gln Trp Leu 530 535 540 Gln Gly Gly Phe Leu Ala Tyr Gln Asp Asp Ser His Arg Thr Pro Asn 545 550 555 560 Thr Asp Ser Gly Asn Asn Arg Lys Leu Gly Arg Gln Pro Ile Asn Ile 565 570 575 Asp Gly Ser Lys Asp Thr Thr Asp Gly Lys Gly Ser Glu Phe Leu Leu 580 585 590 Ala Asn Asp Ile Asp Asn Ser Asn Pro Ile Val Gln Ala Glu Gln Leu 595 600 605 Asn Trp Leu His Tyr Leu Met Asn Phe Gly Ser Ile Thr Gly Asn Asn 610 615 620 Asp Asn Ala Asn Phe Asp Gly Ile Arg Val Asp Ala Val Asp Asn Val 625 630 635 640 Asp Ala Asp Leu Leu Lys Ile Ala Gly Asp Tyr Phe Lys Ala Leu Tyr 645 650 655 Gly Thr Asp Lys Ser Asp Ala Asn Ala Asn Lys His Leu Ser Ile Leu 660 665 670 Glu Asp Trp Asn Gly Lys Asp Pro Gln Tyr Val Asn Gln Gln Gly Asn 675 680 685 Ala Gln Leu Thr Met Asp Tyr Thr Val Thr Ser Gln Phe Gly Asn Ser 690 695 700 Leu Thr His Gly Ala Asn Asn Arg Ser Asn Met Trp Tyr Phe Leu Asp 705 710 715 720 Thr Gly Tyr Tyr Leu Asn Gly Asp Leu Asn Lys Lys Ile Val Asp Lys 725 730 735 Asn Arg Pro Asn Ser Gly Thr Leu Val Asn Arg Ile Ala Asn Ser Gly 740 745 750 Asp Thr Lys Val Ile Pro Asn Tyr Ser Phe Val Arg Ala His Asp Tyr 755 760 765 Asp Ala Gln Asp Pro Ile Arg Lys Ala Met Ile Asp His Gly Ile Ile 770 775 780 Lys Asn Met Gln Asp Thr Phe Thr Phe Asp Gln Leu Ala Gln Gly Met 785 790 795 800 Glu Phe Tyr Tyr Lys Asp Gln Glu Asn Pro Ser Gly Phe Lys Lys Tyr 805 810 815 Asn Asp Tyr Asn Leu Pro Ser Ala Tyr Ala Met Leu Leu Thr Asn Lys 820 825 830 Asp Thr Val Pro Arg Val Tyr Tyr Gly Asp Met Tyr Leu Glu Gly Gly 835 840 845 Gln Tyr Met Glu Lys Gly Thr Ile Tyr Asn Pro Val Ile Ser Ala Leu 850 855 860 Leu Lys Ala Arg Ile Lys Tyr Val Ser Gly Gly Gln Thr Met Ala Thr 865 870 875 880 Asp Ser Ser Gly Lys Asp Leu Lys Asp Gly Glu Thr Asp Leu Leu Thr 885 890 895 Ser Val Arg Phe Gly Lys Gly Ile Met Thr Ser Asp Gln Thr Thr Thr 900 905 910 Gln Asp Asn Ser Gln Asp Tyr Lys Asn Gln Gly Ile Gly Val Ile Val 915 920 925 Gly Asn Asn Pro Asp Leu Lys Leu Asn Asn Asp Lys Thr Ile Thr Leu 930 935 940 His Met Gly Lys Ala His Lys Asn Gln Leu Tyr Arg Ala Leu Val Leu 945 950 955 960 Ser Asn Asp Ser Gly Ile Asp Val Tyr Asp Ser Asp Asp Lys Ala Pro 965 970 975 Thr Leu Arg Thr Asn Asp Asn Gly Asp Leu Ile Phe His Lys Thr Asn 980 985 990 Thr Phe Val Lys Gln Asp Gly Thr Ile Ile Asn Tyr Glu Met Lys Gly 995 1000 1005 Ser Leu Asn Ala Leu Ile Ser Gly Tyr Leu Gly Val Trp Val Pro Val 1010 1015 1020 Gly Ala Ser Asp Ser Gln Asp Ala Arg Thr Val Ala Thr Glu Ser Ser 025 1030 1035 1040 Ser Ser Asn Asp Gly Ser Val Phe His Ser Asn Ala Ala Leu Asp Ser 1045 1050 1055 Asn Val Ile Tyr Glu Gly Phe Ser Asn Phe Gln Ala Met Pro Thr Ser 1060 1065 1070 Pro Glu Gln Ser Thr Asn Val Val Ile Ala Thr Lys Ala Asn Leu Phe 1075 1080 1085 Lys Glu Leu Gly Ile Thr Ser Phe Glu Leu Ala Pro Gln Tyr Arg Ser 1090 1095 1100 Ser Gly Asp Thr Asn Tyr Gly Gly Met Ser Phe Leu Asp Ser Phe Leu 105 1110 1115 1120 Asn Asn Gly Tyr Ala Phe Thr Asp Arg Tyr Asp Leu Gly Phe Asn Lys 1125 1130 1135 Ala Asp Gly Asn Pro Asn Pro Thr Lys Tyr Gly Thr Asp Gln Asp Leu 1140 1145 1150 Arg Asn Ala Ile Glu Ala Leu His Lys Asn Gly Met Gln Ala Ile Ala 1155 1160 1165 Asp Trp Val Pro Asp Gln Ile Tyr Ala Leu Pro Gly Lys Glu Val Val 1170 1175 1180 Thr Ala Thr Arg Val Asp Glu Arg Gly Asn Gln Leu Lys Asp Thr Asp 185 1190 1195 1200 Phe Val Asn Leu Leu Tyr Val Ala Asn Thr Lys Ser Ser Gly Val Asp 1205 1210 1215 Tyr Gln Ala Lys Tyr Gly Gly Glu Phe Leu Asp Lys Leu Arg Glu Glu 1220 1225 1230 Tyr Pro Ser Leu Phe Lys Gln Asn Gln Val Ser Thr Gly Gln Pro Ile 1235 1240 1245 Asp Ala Ser Thr Lys Ile Lys Gln Trp Ser Ala Lys Tyr Met Asn Gly 1250 1255 1260 Thr Asn Ile Leu His Arg Gly Ala Tyr Tyr Val Leu Lys Asp Trp Ala 265 1270 1275 1280 Thr Asn Gln Tyr Phe Asn Ile Ala Lys Thr Asn Glu Val Phe Leu Pro 1285 1290 1295 Leu Gln Leu Gln Asn Lys Asp Ala Gln Thr Gly Phe Ile Ser Asp Ala 1300 1305 1310 Ser Gly Val Lys Tyr Tyr Ser Ile Ser Gly Tyr Gln Ala Lys Asp Thr 1315 1320 1325 Phe Ile Glu Asp Gly Asn Gly Asn Trp Tyr Tyr Phe Asp Lys Asp Gly 1330 1335 1340 Tyr Met Val Arg Ser Gln Gln Gly Glu Asn Pro Ile Arg Thr Val Glu 345 1350 1355 1360 Thr Ser Val Asn Thr Arg Asn Gly Asn Tyr Tyr Phe Met Pro Asn Gly 1365 1370 1375 Val Glu Leu Arg Lys Gly Phe Gly Thr Asp Asn Ser Gly Asn Val Tyr 1380 1385 1390 Tyr Phe Asp Asp Gln Gly Lys Met Val Arg Asp Lys Tyr Ile Asn Asp 1395 1400 1405 Asp Ala Asn Asn Phe Tyr His Leu Asn Val Asp Gly Thr Met Ser Arg 1410 1415 1420 Gly Leu Phe Lys Phe Asp Ser Asp Thr Leu Gln Tyr Phe Ala Ser Asn 425 1430 1435 1440 Gly Val Gln Ile Lys Asp Ser Tyr Ala Lys Asp Ser Lys Gly Asn Lys 1445 1450 1455 Tyr Tyr Phe Asp Ser Ala Thr Gly Asn Asn Asp Thr Gly Lys Ala Gln 1460 1465 1470 Thr Trp Asp Gly Asn Gly Tyr Tyr Ile Thr Ile Asp Ser Asp Ala Asn 1475 1480 1485 Asn Thr Ile Gly Val Asn Thr Asp Tyr Thr Ala Tyr Ile Thr Ser Ser 1490 1495 1500 Leu Arg Glu Asp Gly Leu Phe Ala Asn Ala Pro Tyr Gly Val Val Thr 505 1510 1515 1520 Lys Asp Gln Asn Gly Asn Asp Leu Lys Trp Gln Tyr Ile Asn His Thr 1525 1530 1535 Lys Gln Tyr Glu Gly Gln Gln Val Gln Val Thr Arg Gln Tyr Thr Asp 1540 1545 1550 Ser Lys Gly Val Ser Trp Asn Leu Ile Thr Phe Ala Gly Gly Asp Leu 1555 1560 1565 Gln Gly Gln Arg Leu Trp Val Asp Ser Arg Ala Leu Thr Met Thr Pro 1570 1575 1580 Phe Lys Thr Met Asn Gln Ile Ser Phe Ile Ser Tyr Ala Asn Arg Asn 585 1590 1595 1600 Asp Gly Leu Phe Leu Asn Ala Pro Tyr Gln Val Lys Gly Tyr Gln Leu 1605 1610 1615 Ala Gly Met Ser Asn Gln Tyr Lys Gly Gln Gln Val Thr Ile Ala Gly 1620 1625 1630 Val Ala Asn Val Ser Gly Lys Asp Trp Ser Leu Ile Ser Phe Asn Gly 1635 1640 1645 Thr Gln Tyr Trp Ile Asp Ser Gln Ala Leu Asn Thr Asn Phe Thr His 1650 1655 1660 Asp Met Asn Gln Lys Val Phe Val Asn Thr Thr Ser Asn Leu Asp Gly 665 1670 1675 1680 Leu Phe Leu Asn Ala Pro Tyr Arg Gln Pro Gly Tyr Lys Leu Ala Gly 1685 1690 1695 Leu Ala Lys Asn Tyr Asn Asn Gln Thr Val Thr Val Ser Gln Gln Tyr 1700 1705 1710 Phe Asp Asp Gln Gly Thr Val Trp Ser Gln Val Val Leu Gly Gly Gln 1715 1720 1725 Thr Val Trp Val Asp Asn His Ala Leu Ala Gln Met Gln Val Ser Asp 1730 1735 1740 Thr Asp Gln Gln Leu Tyr Val Asn Ser Asn Gly Arg Asn Asp Gly Leu 745 1750 1755 1760 Phe Leu Asn Ala Pro Tyr Arg Gly Gln Gly Ser Gln Leu Ile Gly Met 1765 1770 1775 Thr Ala Asp Tyr Asn Gly Gln His Val Gln Val Thr Lys Gln Gly Gln 1780 1785 1790 Asp Ala Tyr Gly Ala Gln Trp Arg Leu Ile Thr Leu Asn Asn Gln Gln 1795 1800 1805 Val Trp Val Asp Ser Arg Ala Leu Ser Thr Thr Ile Met Gln Ala Met 1810 1815 1820 Asn Asp Asn Met Tyr Val Asn Ser Ser Gln Arg Thr Asp Gly Leu Trp 825 1830 1835 1840 Leu Asn Ala Pro Tyr Thr Met Ser Gly Ala Lys Trp Ala Gly Asp Thr 1845 1850 1855 Arg Ser Ala Asn Gly Arg Tyr Val His Ile Ser Lys Ala Tyr Ser Asn 1860 1865 1870 Glu Val Gly Asn Thr Tyr Tyr Leu Thr Asn Leu Asn Gly Gln Ser Thr 1875 1880 1885 Trp Ile Asp Lys Arg Ala Phe Thr Val Thr Phe Asp Gln Val Val Ala 1890 1895 1900 Leu Asn Ala Thr Ile Val Ala Arg Gln Arg Pro Asp Gly Met Phe Lys 905 1910 1915 1920 Thr Ala Pro Tyr Gly Glu Ala Gly Ala Gln Phe Val Asp Tyr Val Thr 1925 1930 1935 Asn Tyr Asn Gln Gln Thr Val Pro Val Thr Lys Gln His Ser Asp Ala 1940 1945 1950 Gln Gly Asn Gln Trp Tyr Leu Ala Thr Val Asn Gly Thr Gln Tyr Trp 1955 1960 1965 Ile Asp Gln Arg Ser Phe Ser Pro Val Val Thr Lys Val Val Asp Tyr 1970 1975 1980 Gln Ala Lys Ile Val Pro Arg Thr Thr Arg Asp Gly Val Phe Ser Gly 985 1990 1995 2000 Ala Pro Tyr Gly Glu Val Asn Ala Lys Leu Val Asn Met Ala Thr Ala 2005 2010 2015 Tyr Gln Asn Gln Val Val His Ala Thr Gly Glu Tyr Thr Asn Ala Ser 2020 2025 2030 Gly Ile Thr Trp Ser Gln Phe Ala Leu Ser Gly Gln Glu Asp Lys Leu 2035 2040 2045 Trp Ile Asp Lys Arg Ala Leu Gln Ala 2050 2055 3 30 DNA Artificial Sequence Description of Artificial Sequence artificial sequence 3 actgcggccg catgccattt acagaaaaag 30 4 30 DNA Artificial Sequence Description of Artificial Sequence artificial sequence 4 actgctcgag ttatgctgac acagcatttc 30 5 7 PRT Leuconostoc mesenteroides 5 Lys Thr Asn Glu Val Phe Leu 1 5 6 7 PRT Leuconostoc mesenteroides 6 Lys Phe Asp Ser Asp Arg Leu 1 5 7 19 PRT Leuconostoc mesenteroides 7 Lys Asn Met Gln Asp Thr Phe Thr Phe Asp Gln Leu Ala Gln Gly Met 1 5 10 15 Glu Phe Tyr 8 15 PRT Leuconostoc mesenteroides 8 Lys Ser Thr Glu Trp Leu Arg Asp Ala Ile Asp Leu Phe Val Lys 1 5 10 15 9 22 PRT Leuconostoc mesenteroides 9 Lys Gly Ser Glu Phe Leu Leu Ala Asn Asp Ile Asp Asn Ser Asn Pro 1 5 10 15 Ile Val Gln Ala Glu Gln 20 10 33 DNA Artificial Sequence Description of Artificial Sequence artificial sequence 10 ytgrtcraan gtraangtrt cytgcatrtt ytt 33 11 24 DNA Artificial Sequence Description of Artificial Sequence artificial sequence 11 gaygcnathg ayytnttygt naar 24 12 837 DNA Leuconostoc mesenteroides 12 gatgcaattg atagttttgt gaagacgcaa gctaattgga ataagcaaac agaagatgaa 60 gctttcgatg gtttgcagtg gcttcaaggg ggattcctag cttatcaaga tgattcacat 120 cggacgccga atactgattc aggaaataac agaaaactag gacgtcaacc aattaatatc 180 gatggttcga aagatacaac tgatggtaaa ggctctgaat tcttattagc taacgatatt 240 gacaactcaa atccgattgt tcaagctgag caattaaact ggctacacta tttaatgaat 300 tttggtagta ttacaggtaa taatgacaat gcgaattttg atggcattcg tgtagatgct 360 gttgataatg ttgatgctga tttactaaaa atagctggcg attattttaa agctctatat 420 ggtacagata aaagcgacgc caatgccaat aagcatttgt ctattttaga agactggaac 480 ggtaaagatc ctcagtatgt taatcaacag ggcaatgcgc aattaacaat ggattacaca 540 gttacttcac agtttggcaa ttctctaaca catggcgcca acaacaggag taacatgtgg 600 tatttcttag atactggcta ttatcttaat ggagatctta ataagaagat agtagataag 660 aaccgtccaa attctggcac tttggttaac agaattgcta attcaggtga tacaaaagtt 720 attccaaatt atagttttgt tagagcacat gattacgatg ctcaagatcc aattagaaaa 780 gccatgattg atcatggtat tattaaaaac atgcaggata ctttcacttt tgaccaa 837 13 2862 DNA Leuconostoc mesenteroides 13 gatcaaatag atgctaccgt tatacgagac gttaaggatt atcccaatct agtcgttttg 60 cgtaccttgt cgaaagctta tggtctggca aacctgagaa tcggctatgg cgtcatgcag 120 gaaccacttt atcaggttat gcaggccgta cgtttaccat ataatttaaa tacctatcaa 180 atcacaggtg cagtagctgc ccttagtgat caactttatc tgcaatcagt tgttgctaag 240 gtgaagtctg aacgtgaaaa atttgaacaa tttttgacga aacaccagtt taagtattat 300 caatcacaaa ccaactttct ctggattaaa gttggtgatg cgaaacgtgt tggtgaggct 360 cttctgtcag aagggtatca aattaatgac cgcctaaatg ccgaatggat tcgcattgca 420 ttaggaactg tgtctgataa tgaggggatg cagcgcattt tattgaattg ttaaaaaata 480 gctaagagag tatgttcttc tcttacctat ttttatttgt aattcctatt atttaatttt 540 gcatgacaat attaatagcg tgttacgatt ctactattta atgttaataa aattaataaa 600 tatggtatta tcttatatgg gtgatagatg caccaaatac tgtatcatgt ctggtcacat 660 gaaagggaga ataattaatg aaacaacaag aaacagttac ccgtaaaaaa ctttataaat 720 ccggtaaggt ttgggttgca gcagctactg catttgcggt attgggggtt tcaactgtaa 780 caacagtcca tgcggataca aattcgaatg tcgctgttaa gcaaataaat aatacaggaa 840 ccaatgattc tggcgaaaaa aaggtaccgg ttccatcaac taataatgat agtttgaagc 900 aaggaacaga tggtttttgg tatgattcag acggcaatcg tgtcgatcag aagaccaatc 960 agattctgct tactgcggaa caacttaaaa aaaataacga aaaaaattta tcagtaatca 1020 gtgatgatac atcaaaaaaa gatgatgaaa atatttctaa gcagaccaaa attgctaatc 1080 aacaaacagt agatactgct aaaggcctga ctaccagtaa tttatctgat cccatcactg 1140 ggggtcacta tgaaaatcac aatggctact ttgtttatat agatgcttca ggaaaacaag 1200 taacaggttt gcaaaatatt gatggtaatt tacaatattt tgatgacaat ggatatcaag 1260 tcaagggatc cttccgagat gtcaacggca agcatatcta ttttgattca gtaacaggga 1320 aagctagttc aaatgttgat attgttaacg gtaaagctca aggatatgat gcgcaaggca 1380 accaattaaa gaaaagttat gtcgccgata gttctgggca aacttactat tttgatggta 1440 atggccaacc gttaatcggc ttgcaaacaa ttgatgggaa cctacaatat tttaaccaac 1500 aaggggttca aataaagggt ggtttccaag atgttaacaa taaacgtatt tattttgcac 1560 caaacacagg taatgccgtt gccaatactg aaataattaa cggtaaatta caggggcgtg 1620 acgcaaatgg taaccaggta aagaatgcat ttagtaaaga tgttgcagga aatacatttt 1680 attttgacgc aaacggtgtg atgttaacag ggttgcaaac tatttcagga aagacatatt 1740 atcttgatga acaaggacac ctgagaaaaa attacgcggg aacattcaat aatcagttta 1800 tgtacttcga tgctgataca ggtgcgggta aaacagcgat tgaatatcaa tttgatcaag 1860 gattggtatc acaaagtaat gaaaatactc ctcacaatgc cgcaaagtct tatgataaaa 1920 gtagttttga aaatgttgat ggttacttaa cagcagatac atggtatcgt ccaaccgata 1980 ttttaaaaaa tggagatact tggacggcat ctaccgaaac tgatatgcgt ccgcttttaa 2040 tgacatggtg gcctgacaaa caaacacaag caaattactt gaattttatg tctagtaaag 2100 gacttggtat aacgaccact tatacagcag ctacgtcaca aaaaacacta aatgacgcag 2160 cctttgttat tcaaacagca attgaacaac aaatatcttt gaaaaaaagt actgagtggt 2220 tacgtgatgc aattgatagt tttgtgaaga cgcaagctaa ttggaataag caaacagaag 2280 atgaagcttt cgatggtttg cagtggcttc aagggggatt cctagcttat caagatgatt 2340 cacatcggac gccgaatact gattcaggaa ataacagaaa actaggacgt caaccaatta 2400 atatcgatgg ttcgaaagat acaactgatg gtaaaggctc tgaattctta ttagctaacg 2460 atattgacaa ctcaaatccg attgttcaag ctgagcaatt aaactggcta cactatttaa 2520 tgaattttgg tagtattaca ggtaataatg acaatgcgaa ttttgatggc attcgtgtag 2580 atgctgttga taatgttgat gctgatttac taaaaatagc tggcgattat tttaaagctc 2640 tatatggtac agataaaagc gacgccaatg ccaataagca tttgtctatt ttagaagact 2700 ggaacggtaa agatcctcag tatgttaatc aacagggcaa tgcgcaatta acaatggatt 2760 acacagttac ttcacagttt ggcaattctc taacacatgg cgccaacaac aggagtaaca 2820 tgtggtattt cttagatact ggctattatc ttaatggaga tc 2862 14 3970 DNA Leuconostoc mesenteroides 14 gatcaaggat tggtatcaca aagtaatgaa aatactcctc acaatgccgc aaagtcttat 60 gataaaagta gttttgaaaa tgttgatggt tacttaacag cagatacatg gtatcgtcca 120 accgatattt taaaaaatgg agatacttgg acggcatcta ccgaaactga tatgcgtccg 180 cttttaatga catggtggcc tgacaaacaa acacaagcaa attacttgaa ttttatgtct 240 agtaaaggac ttggtataac gaccacttat acagcagcta cgtcacaaaa aacactaaat 300 gacgcagcct ttgttattca aacagcaatt gaacaacaaa tatctttgaa aaaaagtact 360 gagtggttac gtgatgcaat tgatagtttt gtgaagacgc aagctaattg gaataagcaa 420 acagaagatg aagctttcga tggtttgcag tggcttcaag ggggattcct agcttatcaa 480 gatgattcac atcggacgcc gaatactgat tcaggaaata acagaaaact aggacgtcaa 540 ccaattaata tcgatggttc gaaagataca actgatggta aaggctctga attcttatta 600 gctaacgata ttgacaactc aaatccgatt gttcaagctg agcaattaaa ctggctacac 660 tatttaatga attttggtag tattacaggt aataatgaca atgcgaattt tgatggcatt 720 cgtgtagatg ctgttgataa tgttgatgct gatttactaa aaatagctgg cgattatttt 780 aaagctctat atggtacaga taaaagcgac gccaatgcca ataagcattt gtctatttta 840 gaagactgga acggtaaaga tcctcagtat gttaatcaac agggcaatgc gcaattaaca 900 atggattaca cagttacttc acagtttggc aattctctaa cacatggcgc caacaacagg 960 agtaacatgt ggtatttctt agatactggc tattatctta atggagatct taataagaag 1020 atagtagata agaaccgtcc aaattctggc actttggtta acagaattgc taattcaggt 1080 gatacaaaag ttattccaaa ttatagtttt gttagagcac atgattacga tgctcaagat 1140 ccaattagaa aagccatgat tgatcatggt attattaaaa acatgcagga tactttcact 1200 tttgaccaac tggctcaggg aatggaattc tactataaag atcaagagaa tccgtctggt 1260 ttcaaaaagt ataacgatta taacttacct agtgcttatg caatgttgtt gactaataag 1320 gatactgtac ctcgtgtcta ttatggagat atgtacctcg aaggcgggca atatatggaa 1380 aaagggacga tttacaatcc tgtcatttca gcgttgctca aagctagaat aaaatatgtt 1440 tctggtgggc aaacaatggc taccgatagt tctggaaaag accttaaaga tggcgaaact 1500 gatttgttaa caagtgttcg atttggtaaa ggaattatga catcagatca aaccacaaca 1560 caagacaata gccaagatta taaaaatcaa ggcatcggtg tcattgttgg taataaccct 1620 gaccttaagt tgaacaatga taagaccatt accttgcata tgggaaaggc gcataagaat 1680 caactttacc gtgccttagt attatcaaat gactcaggaa ttgatgttta tgatagtgat 1740 gataaagcac caactttgag aacaaatgac aacggtgact tgattttcca taagacaaat 1800 acgtttgtga agcaagatgg aactattata aattacgaaa tgaagggatc attaaatgct 1860 ttaatttcag gttatttagg tgtctgggtg ccagttggag ctagtgattc acaagatgct 1920 cgtacagtgg caactgagtc atcatcaagt aatgatggtt ctgtattcca ttcaaatgct 1980 gcattagatt ctaatgttat atatgaaggc ttttcaaact ttcaagcgat gccgacttct 2040 cctgagcaaa gtacaaatgt tgttattgca acaaaggcta acttatttaa agaattaggt 2100 attactagtt ttgagttagc acctcaatat aggtctagtg gtgacactaa ttacggtggc 2160 atgtcattct tagattcttt cttaaataat ggttatgcat ttaccgatag atatgattta 2220 ggctttaaca aagcagacgg gaatcctaac ccaacaaagt atggaacaga tcaagattta 2280 cgtaatgcaa tagaggcatt acacaaaaac ggcatgcagg ctatagctga ttgggttcct 2340 gaccaaatat atgctttacc aggaaaggaa gttgttaccg ctactagagt agacgaacgg 2400 ggaaatcaac taaaagacac agattttgtc aacttactct atgttgctaa tactaaaagt 2460 agtggtgtgg attatcaggc aaagtatggc ggcgaatttt tagataaatt aagagaagag 2520 tacccatcgt tattcaaaca gaaccaagta tcgacaggtc agccaattga tgcttctaca 2580 aaaattaagc aatggtcagc taaatatatg aatgggacca atattttaca tcgaggtgct 2640 tattatgttt tgaaagactg ggctactaac cagtatttta acattgcaaa aacgaatgaa 2700 gtatttttgc cactacagtt gcagaataaa gatgcgcaaa ctggtttcat tagtgatgcc 2760 tccggtgtaa aatattactc aattagtggt tatcaagcaa aagatacttt tattgaagat 2820 ggtaatggga attggtatta ctttgataaa gatggttaca tggtgcgttc gcagcaagga 2880 gaaaatccta taagaacagt cgaaactagt gtcaacacac gaaacggtaa ttattacttt 2940 atgccaaatg gtgtcgagtt gcgcaaaggc tttggaacgg ataatagtgg taatgtctat 3000 tattttgatg atcaaggtaa gatggtgaga gataaataca ttaacgatga tgctaataat 3060 ttttatcact taaatgttga tgggactatg tctcgaggac tatttaaatt tgattctgat 3120 actctacagt attttgctag taatggtgtc caaataaaag atagttatgc gaaggatagt 3180 aaaggcaata aatattattt tgactcagct acaggaaata acgatactgg gaaagcccaa 3240 acttgggatg gtaatggcta ctatattact attgattctg atgcgaacaa tacaattggg 3300 gttaacacag actacactgc ctacatcact agctcgctgc gcgaagatgg cttatttgct 3360 aacgcacctt acggtgttgt aacaaaagac caaaatggta acgatcttaa gtggcagtat 3420 attaaccata cgaaacagta cgaagggcaa caagtgcaag tcacgcgtca atacacagac 3480 agtaagggag tcagctggaa cttaattacc tttgctggtg gtgatttaca aggacaaagg 3540 ctttgggtgg atagtcgtgc gttaactatg acaccattta aaacgatgaa ccaaataagc 3600 ttcattagtt atgctaaccg caatgatggg ttgtttttga atgcgccata ccaagtcaag 3660 gggtatcaat tagctgggat gtccaaccaa tacaagggcc aacaagtgac cattgctggg 3720 gtggcgaacg tttctggaaa agactggagt ctgattagtt ttaatgggac acagtactgg 3780 attgatagtc aggcattgaa taccaatttc acacatgaca tgaaccaaaa ggtctttgtc 3840 aatacaacta gtaatcttga tgggttattc ttaaatgcgc cataccgtca accgggttat 3900 aagttagccg gtttggctaa aaattacaac aaccaaacgg ttactgttag tcaacagtac 3960 tttgatgatc 3970 15 1917 DNA Leuconostoc mesenteroides 15 gatcaaggta agatggtgag agataaatac attaacgatg atgctaataa tttttatcac 60 ttaaatgttg atgggactat gtctcgagga ctatttaaat ttgattctga tactctacag 120 tattttgcta gtaatggtgt ccaaataaaa gatagttatg cgaaggatag taaaggcaat 180 aaatattatt ttgactcagc tacaggaaat aacgatactg ggaaagccca aacttgggat 240 ggtaatggct actatattac tattgattct gatgcgaaca atacaattgg ggttaacaca 300 gactacactg cctacatcac tagctcgctg cgcgaagatg gcttatttgc taacgcacct 360 tacggtgttg taacaaaaga ccaaaatggt aacgatctta agtggcagta tattaaccat 420 acgaaacagt acgaagggca acaagtgcaa gtcacgcgtc aatacacaga cagtaaggga 480 gtcagctgga acttaattac ctttgctggt ggtgatttac aaggacaaag gctttgggtg 540 gatagtcgtg cgttaactat gacaccattt aaaacgatga accaaataag cttcattagt 600 tatgctaacc gcaatgatgg gttgtttttg aatgcgccat accaagtcaa ggggtatcaa 660 ttagctggga tgtccaacca atacaagggc caacaagtga ccattgctgg ggtggcgaac 720 gtttctggaa aagactggag tctgattagt tttaatggga cacagtactg gattgatagt 780 caggcattga ataccaattt cacacatgac atgaaccaaa aggtctttgt caatacaact 840 agtaatcttg atgggttatt cttaaatgcg ccataccgtc aaccgggtta taagttagcc 900 ggtttggcta aaaattacaa caaccaaacg gttactgtta gtcaacagta ctttgatgat 960 caaggcacgg tctggagtca ggttgtcctt gggggtcaga cggtctgggt tgataaccat 1020 gcattggcac agatgcaagt tagtgataca gaccaacagc tctatgtgaa tagcaatggt 1080 cggaatgatg ggttattctt gaatgcgcca tatcgtggtc aagggtcaca actgataggc 1140 atgacggcag attataatgg gcaacatgta caagtgacca agcaagggca agatgcctat 1200 ggtgcacaat ggcgtcttat tacgctaaat aatcaacagg tctgggttga tagtcgcgct 1260 ttgagcacaa caatcatgca agccatgaat gataatatgt atgtaaatag cagccaacgg 1320 acagatggct tgtggttaaa cgcaccttat acgatgagtg gggctaaatg ggctggtgat 1380 acacgttcag ctaatgggcg ctatgtccat atttcaaaag cttattcaaa cgaagtcggc 1440 aatacatatt acttgacgaa tttgaatggt caaagcacat ggattgacaa gcgggcgttt 1500 actgtgacct tcgatcaggt ggtggcatta aatgcaacga ttgtggcacg ccaacgacca 1560 gatgggatgt ttaagacagc accatatggt gaagcggggg cgcagtttgt cgattatgtg 1620 acaaactata accagcaaac cgtgccagta acaaagcaac attcagatgc tcaggggaat 1680 caatggtact tagcgacagt gaatgggaca caatactgga ttgatcaacg gtcattttca 1740 ccagtagtaa cgaaggtggt tgattatcaa gctaagattg tgccacggac aacacgtgat 1800 ggtgtgttta gtggcgcacc ctatggggaa gtgaatgcta agctagttaa catggcaact 1860 gcgtatcaaa atcaagttgt ccatgcgaca ggggaatata cgaatgcttc agggatc 1917 16 4066 DNA Leuconostoc mesenteroides 16 gatcttaagt ggcagtatat taaccatacg aaacagtacg aagggcaaca agtgcaagtc 60 acgcgtcaat acacagacag taagggagtc agctggaact taattacctt tgctggtggt 120 gatttacaag gacaaaggct ttgggtggat agtcgtgcgt taactatgac accatttaaa 180 acgatgaacc aaataagctt cattagttat gctaaccgca atgatgggtt gtttttgaat 240 gcgccatacc aagtcaaggg gtatcaatta gctgggatgt ccaaccaata caagggccaa 300 caagtgacca ttgctggggt ggcgaacgtt tctggaaaag actggagtct gattagtttt 360 aatgggacac agtactggat tgatagtcag gcattgaata ccaatttcac acatgacatg 420 aaccaaaagg tctttgtcaa tacaactagt aatcttgatg ggttattctt aaatgcgcca 480 taccgtcaac cgggttataa gttagccggt ttggctaaaa attacaacaa ccaaacggtt 540 actgttagtc aacagtactt tgatgatcaa ggcacggtct ggagtcaggt tgtccttggg 600 ggtcagacgg tctgggttga taaccatgca ttggcacaga tgcaagttag tgatacagac 660 caacagctct atgtgaatag caatggtcgg aatgatgggt tattcttgaa tgcgccatat 720 cgtggtcaag ggtcacaact gataggcatg acggcagatt ataatgggca acatgtacaa 780 gtgaccaagc aagggcaaga tgcctatggt gcacaatggc gtcttattac gctaaataat 840 caacaggtct gggttgatag tcgcgctttg agcacaacaa tcatgcaagc catgaatgat 900 aatatgtatg taaatagcag ccaacggaca gatggcttgt ggttaaacgc accttatacg 960 atgagtgggg ctaaatgggc tggtgataca cgttcagcta atgggcgcta tgtccatatt 1020 tcaaaagctt attcaaacga agtcggcaat acatattact tgacgaattt gaatggtcaa 1080 agcacatgga ttgacaagcg ggcgtttact gtgaccttcg atcaggtggt ggcattaaat 1140 gcaacgattg tggcacgcca acgaccagat gggatgttta agacagcacc atatggtgaa 1200 gcgggggcgc agtttgtcga ttatgtgaca aactataacc agcaaaccgt gccagtaaca 1260 aagcaacatt cagatgctca ggggaatcaa tggtacttag cgacagtgaa tgggacacaa 1320 tactggattg atcaacggtc attttcacca gtagtaacga aggtggttga ttatcaagct 1380 aagattgtgc cacggacaac acgtgatggt gtgtttagtg gcgcacccta tggggaagtg 1440 aatgctaagc tagttaacat ggcaactgcg tatcaaaatc aagttgtcca tgcgacaggg 1500 gaatatacga atgcttcagg gatcacatgg agtcagttcg cgttaagcgg gcaagaagac 1560 aagctatgga ttgataagcg tgctttgcaa gcttaaggga aggattcgac aaaggagggt 1620 aacattatca gcggatggtg ttatcctcct ttcctgtact cagtatttcc caaataattg 1680 agacagtttc atgacaaatc aacaaaacta gtgtcaatgc ctcggttatg gggtaaacta 1740 ctattagtta aagggttgtt gcataataat atcacattca atatattatg tatttttatc 1800 tgattatgtg attttttgag atttggagcg aaaatgaata aagtaataat taataaaagt 1860 ttctgtgttt tggtaatgag tttgttgtcg atatttctat tctcattaag agtagacgct 1920 cgttccaata gtggctacaa tcaaatatct tttaatcaac atgaaattgc ttatgcgcct 1980 tttagtcaag taccttggta tgcaactgtg aatgtcggaa tgtctgcaga caaaaataat 2040 atctatacag ctattgatat ggggccatag tatcaaggaa cttctttttt tccgtggtgg 2100 tatcaacatg ataattatga ttatcatgat ggttatcaac ttgcgattga caatcaatcg 2160 cttttcatag aaatggttga tacaggaagg tcgtcgtttg atgttattga gttgtataca 2220 ggtaaaaaag ttggttatgg aaaattcaca gcctataact ataacaagac ttcatggcag 2280 tttcaaatat ctttaaaggc gataaagaaa attttaaata ataacatatc agaaaatgcg 2340 acaattagtt tgtacaatgg ttatctattc aaacaagccg aaagtatcac gtatgctggt 2400 tcaccaacag ggccatggtt acttgccggt attggtttgg tttttgctgg tgggggctat 2460 tacctgcaaa atcagcgccg aaaaacgatt acggcatcat caacaaacga ggtaacccat 2520 gcttaataat gctgttatta ttggtctaat tattatttgg gtctatgtat tatctgttct 2580 gaagcgtgct aaaacggatg cgttttattt tttggctggc agcgcaggct tgttcgtcat 2640 tcttctttta tggagtaaac cttatggtgt ttggttgttt tcgaccattc tcacttggtc 2700 ggccggggtt gttggtcatc tcactggctt atttgatact ttctatgcgt cacatgttat 2760 tcaggttgtg gcgaatcatc ataccagcat tttattggtt gattatgaat gttcaggcat 2820 tattgaaaca acggcatttt ggggattaat tgccttttat cctgtgtatg atgcacaaaa 2880 gcggttaatg ttggcgctta ttggggcatt atggtttttc cttgcaaata cgttacgact 2940 atcttttgtt gcagttgtaa tttattattt tggcgatggc gctttttatg ttgctcattc 3000 aattatcgga cgcctgttgt tctattcaat tgtaatcttg ctttattatc tagtcttcat 3060 aaaggggcaa cttgttaatc aaatgctcaa aaaacaggga taaactatgt cattttattt 3120 acatcaattt acttatcagt taggtttttg gttcacttgg ttgctcattc cgtttgttgt 3180 ggaaattttc ccagctatta tttcaatcta gttttgataa aaacatcaaa aaagcatcaa 3240 gtgatgcaag aaccattgaa attaccaatg gtatctattg tattacctat atataattca 3300 ggacaaacat tataccagtg tattcagtcg attagtcaat caacctatcc aaaacaatta 3360 atccaaatta ttgccgtgaa taatcaaagc actgataaca gttttacagt gtttaatcag 3420 gctcaagctg atttcccaat acttagaatg cagtggatga acacagatca aggtaaagcg 3480 cgtgcactaa atgctgctat ttataatagt atggggcaat atattattaa tttggatact 3540 gatggttggt tagaacccaa tgccttaaaa cggtttgtgc tttattttga aaatcactca 3600 gaaattgatg tagcaactgg tacgattctg acacaaaaaa aaatgattca aaaaacgcaa 3660 agtaaatggc ttaaattgct acagttaaac gaatattttg agtatgcaca atcattctta 3720 tcaggccgta gtattgaaaa ccgtggtaat cgtttgttca caatgtcagg tgcattttca 3780 gcgtttagac gtgatgtatt agttcagaca tttatgtata atgttgacac ggttggtgaa 3840 gatactgata tgacatttca actgcgattc cgcctaggca agcgtattgg tttctgtgat 3900 gatgccatgt tttatgttga accaatatca ggttatagtg aactttattt acaacggcag 3960 cgttggcagc gtgggcaaat tgaagtcgca caaaatttca tgcagaataa gttgagtgtc 4020 cgtcagattt ttactaactt tatgattagt cgattaatga ttgatc 4066 17 7387 DNA Leuconostoc mesenteroides 17 gatcaaatag atgctaccgt tatacgagac gttaaggatt atcccaatct agtcgttttg 60 cgtaccttgt cgaaagctta tggtctggca aacctgagaa tcggctatgg cgtcatgcag 120 gaaccacttt atcaggttat gcaggccgta cgtttaccat ataatttaaa tacctatcaa 180 atcacaggtg cagtagctgc ccttagtgat caactttatc tgcaatcagt tgttgctaag 240 gtgaagtctg aacgtgaaaa atttgaacaa tttttgacga aacaccagtt taagtattat 300 caatcacaaa ccaactttct ctggattaaa gttggtgatg cgaaacgtgt tggtgaggct 360 cttctgtcag aagggtatca aattaatgac cgcctaaatg ccgaatggat tcgcattgca 420 ttaggaactg tgtctgataa tgaggggatg cagcgcattt tattgaattg ttaaaaaata 480 gctaagagag tatgttcttc tcttacctat ttttatttgt aattcctatt atttaatttt 540 gcatgacaat attaatagcg tgttacgatt ctactattta atgttaataa aattaataaa 600 tatggtatta tcttatatgg gtgatagatg caccaaatac tgtatcatgt ctggtcacat 660 gaaagggaga ataattaatg aaacaacaag aaacagttac ccgtaaaaaa ctttataaat 720 ccggtaaggt ttgggttgca gcagctactg catttgcggt attgggggtt tcaactgtaa 780 caacagtcca tgcggataca aattcgaatg tcgctgttaa gcaaataaat aatacaggaa 840 ccaatgattc tggcgaaaaa aaggtaccgg ttccatcaac taataatgat agtttgaagc 900 aaggaacaga tggtttttgg tatgattcag acggcaatcg tgtcgatcag aagaccaatc 960 agattctgct tactgcggaa caacttaaaa aaaataacga aaaaaattta tcagtaatca 1020 gtgatgatac atcaaaaaaa gatgatgaaa atatttctaa gcagaccaaa attgctaatc 1080 aacaaacagt agatactgct aaaggcctga ctaccagtaa tttatctgat cccatcactg 1140 ggggtcacta tgaaaatcac aatggctact ttgtttatat agatgcttca ggaaaacaag 1200 taacaggttt gcaaaatatt gatggtaatt tacaatattt tgatgacaat ggatatcaag 1260 tcaagggatc cttccgagat gtcaacggca agcatatcta ttttgattca gtaacaggga 1320 aagctagttc aaatgttgat attgttaacg gtaaagctca aggatatgat gcgcaaggca 1380 accaattaaa gaaaagttat gtcgccgata gttctgggca aacttactat tttgatggta 1440 atggccaacc gttaatcggc ttgcaaacaa ttgatgggaa cctacaatat tttaaccaac 1500 aaggggttca aataaagggt ggtttccaag atgttaacaa taaacgtatt tattttgcac 1560 caaacacagg taatgccgtt gccaatactg aaataattaa cggtaaatta caggggcgtg 1620 acgcaaatgg taaccaggta aagaatgcat ttagtaaaga tgttgcagga aatacatttt 1680 attttgacgc aaacggtgtg atgttaacag ggttgcaaac tatttcagga aagacatatt 1740 atcttgatga acaaggacac ctgagaaaaa attacgcggg aacattcaat aatcagttta 1800 tgtacttcga tgctgataca ggtgcgggta aaacagcgat tgaatatcaa tttgatcaag 1860 gattggtatc acaaagtaat gaaaatactc ctcacaatgc cgcaaagtct tatgataaaa 1920 gtagttttga aaatgttgat ggttacttaa cagcagatac atggtatcgt ccaaccgata 1980 ttttaaaaaa tggagatact tggacggcat ctaccgaaac tgatatgcgt ccgcttttaa 2040 tgacatggtg gcctgacaaa caaacacaag caaattactt gaattttatg tctagtaaag 2100 gacttggtat aacgaccact tatacagcag ctacgtcaca aaaaacacta aatgacgcag 2160 cctttgttat tcaaacagca attgaacaac aaatatcttt gaaaaaaagt actgagtggt 2220 tacgtgatgc aattgatagt tttgtgaaga cgcaagctaa ttggaataag caaacagaag 2280 atgaagcttt cgatggtttg cagtggcttc aagggggatt cctagcttat caagatgatt 2340 cacatcggac gccgaatact gattcaggaa ataacagaaa actaggacgt caaccaatta 2400 atatcgatgg ttcgaaagat acaactgatg gtaaaggctc tgaattctta ttagctaacg 2460 atattgacaa ctcaaatccg attgttcaag ctgagcaatt aaactggcta cactatttaa 2520 tgaattttgg tagtattaca ggtaataatg acaatgcgaa ttttgatggc attcgtgtag 2580 atgctgttga taatgttgat gctgatttac taaaaatagc tggcgattat tttaaagctc 2640 tatatggtac agataaaagc gacgccaatg ccaataagca tttgtctatt ttagaagact 2700 ggaacggtaa agatcctcag tatgttaatc aacagggcaa tgcgcaatta acaatggatt 2760 acacagttac ttcacagttt ggcaattctc taacacatgg cgccaacaac aggagtaaca 2820 tgtggtattt cttagatact ggctattatc ttaatggaga tcttaataag aagatagtag 2880 ataagaaccg tccaaattct ggcactttgg ttaacagaat tgctaattca ggtgatacaa 2940 aagttattcc aaattatagt tttgttagag cacatgatta cgatgctcaa gatccaatta 3000 gaaaagccat gattgatcat ggtattatta aaaacatgca ggatactttc acttttgacc 3060 aactggctca gggaatggaa ttctactata aagatcaaga gaatccgtct ggtttcaaaa 3120 agtataacga ttataactta cctagtgctt atgcaatgtt gttgactaat aaggatactg 3180 tacctcgtgt ctattatgga gatatgtacc tcgaaggcgg gcaatatatg gaaaaaggga 3240 cgatttacaa tcctgtcatt tcagcgttgc tcaaagctag aataaaatat gtttctggtg 3300 ggcaaacaat ggctaccgat agttctggaa aagaccttaa agatggcgaa actgatttgt 3360 taacaagtgt tcgatttggt aaaggaatta tgacatcaga tcaaaccaca acacaagaca 3420 atagccaaga ttataaaaat caaggcatcg gtgtcattgt tggtaataac cctgacctta 3480 agttgaacaa tgataagacc attaccttgc atatgggaaa ggcgcataag aatcaacttt 3540 accgtgcctt agtattatca aatgactcag gaattgatgt ttatgatagt gatgataaag 3600 caccaacttt gagaacaaat gacaacggtg acttgatttt ccataagaca aatacgtttg 3660 tgaagcaaga tggaactatt ataaattacg aaatgaaggg atcattaaat gctttaattt 3720 caggttattt aggtgtctgg gtgccagttg gagctagtga ttcacaagat gctcgtacag 3780 tggcaactga gtcatcatca agtaatgatg gttctgtatt ccattcaaat gctgcattag 3840 attctaatgt tatatatgaa ggcttttcaa actttcaagc gatgccgact tctcctgagc 3900 aaagtacaaa tgttgttatt gcaacaaagg ctaacttatt taaagaatta ggtattacta 3960 gttttgagtt agcacctcaa tataggtcta gtggtgacac taattacggt ggcatgtcat 4020 tcttagattc tttcttaaat aatggttatg catttaccga tagatatgat ttaggcttta 4080 acaaagcaga cgggaatcct aacccaacaa agtatggaac agatcaagat ttacgtaatg 4140 caatagaggc attacacaaa aacggcatgc aggctatagc tgattgggtt cctgaccaaa 4200 tatatgcttt accaggaaag gaagttgtta ccgctactag agtagacgaa cggggaaatc 4260 aactaaaaga cacagatttt gtcaacttac tctatgttgc taatactaaa agtagtggtg 4320 tggattatca ggcaaagtat ggcggcgaat ttttagataa attaagagaa gagtacccat 4380 cgttattcaa acagaaccaa gtatcgacag gtcagccaat tgatgcttct acaaaaatta 4440 agcaatggtc agctaaatat atgaatggga ccaatatttt acatcgaggt gcttattatg 4500 ttttgaaaga ctgggctact aaccagtatt ttaacattgc aaaaacgaat gaagtatttt 4560 tgccactaca gttgcagaat aaagatgcgc aaactggttt cattagtgat gcctccggtg 4620 taaaatatta ctcaattagt ggttatcaag caaaagatac ttttattgaa gatggtaatg 4680 ggaattggta ttactttgat aaagatggtt acatggtgcg ttcgcagcaa ggagaaaatc 4740 ctataagaac agtcgaaact agtgtcaaca cacgaaacgg taattattac tttatgccaa 4800 atggtgtcga gttgcgcaaa ggctttggaa cggataatag tggtaatgtc tattattttg 4860 atgatcaagg taagatggtg agagataaat acattaacga tgatgctaat aatttttatc 4920 acttaaatgt tgatgggact atgtctcgag gactatttaa atttgattct gatactctac 4980 agtattttgc tagtaatggt gtccaaataa aagatagtta tgcgaaggat agtaaaggca 5040 ataaatatta ttttgactca gctacaggaa ataacgatac tgggaaagcc caaacttggg 5100 atggtaatgg ctactatatt actattgatt ctgatgcgaa caatacaatt ggggttaaca 5160 cagactacac tgcctacatc actagctcgc tgcgcgaaga tggcttattt gctaacgcac 5220 cttacggtgt tgtaacaaaa gaccaaaatg gtaacgatct taagtggcag tatattaacc 5280 atacgaaaca gtacgaaggg caacaagtgc aagtcacgcg tcaatacaca gacagtaagg 5340 gagtcagctg gaacttaatt acctttgctg gtggtgattt acaaggacaa aggctttggg 5400 tggatagtcg tgcgttaact atgacaccat ttaaaacgat gaaccaaata agcttcatta 5460 gttatgctaa ccgcaatgat gggttgtttt tgaatgcgcc ataccaagtc aaggggtatc 5520 aattagctgg gatgtccaac caatacaagg gccaacaagt gaccattgct ggggtggcga 5580 acgtttctgg aaaagactgg agtctgatta gttttaatgg gacacagtac tggattgata 5640 gtcaggcatt gaataccaat ttcacacatg acatgaacca aaaggtcttt gtcaatacaa 5700 ctagtaatct tgatgggtta ttcttaaatg cgccataccg tcaaccgggt tataagttag 5760 ccggtttggc taaaaattac aacaaccaaa cggttactgt tagtcaacag tactttgatg 5820 atcaaggcac ggtctggagt caggttgtcc ttgggggtca gacggtctgg gttgataacc 5880 atgcattggc acagatgcaa gttagtgata cagaccaaca gctctatgtg aatagcaatg 5940 gtcggaatga tgggttattc ttgaatgcgc catatcgtgg tcaagggtca caactgatag 6000 gcatgacggc agattataat gggcaacatg tacaagtgac caagcaaggg caagatgcct 6060 atggtgcaca atggcgtctt attacgctaa ataatcaaca ggtctgggtt gatagtcgcg 6120 ctttgagcac aacaatcatg caagccatga atgataatat gtatgtaaat agcagccaac 6180 ggacagatgg cttgtggtta aacgcacctt atacgatgag tggggctaaa tgggctggtg 6240 atacacgttc agctaatggg cgctatgtcc atatttcaaa agcttattca aacgaagtcg 6300 gcaatacata ttacttgacg aatttgaatg gtcaaagcac atggattgac aagcgggcgt 6360 ttactgtgac cttcgatcag gtggtggcat taaatgcaac gattgtggca cgccaacgac 6420 cagatgggat gtttaagaca gcaccatatg gtgaagcggg ggcgcagttt gtcgattatg 6480 tgacaaacta taaccagcaa accgtgccag taacaaagca acattcagat gctcagggga 6540 atcaatggta cttagcgaca gtgaatggga cacaatactg gattgatcaa cggtcatttt 6600 caccagtagt aacgaaggtg gttgattatc aagctaagat tgtgccacgg acaacacgtg 6660 atggtgtgtt tagtggcgca ccctatgggg aagtgaatgc taagctagtt aacatggcaa 6720 ctgcgtatca aaatcaagtt gtccatgcga caggggaata tacgaatgct tcagggatca 6780 catggagtca gttcgcgtta agcgggcaag aagacaagct atggattgat aagcgtgctt 6840 tgcaagctta agggaaggat tcgacaaagg agggtaacat tatcagcgga tggtgttatc 6900 ctcctttcct gtactcagta tttcccaaat aattgagaca gtttcatgac aaatcaacaa 6960 aactagtgtc aatgcctcgg ttatggggta aactactatt agttaaaggg ttgttgcata 7020 ataatatcac attcaatata ttatgtattt ttatctgatt atgtgatttt ttgagatttg 7080 gagcgaaaat gaataaagta ataattaata aaagtttctg tgttttggta atgagtttgt 7140 tgtcgatatt tctattctca ttaagagtag acgctcgttc caatagtggc tacaatcaaa 7200 tatcttttaa tcaacatgaa attgcttatg cgccttttag tcaagtacct tggtatgcaa 7260 ctgtgaatgt cggaatgtct gcagacaaaa ataatatcta tacagctatt gatatggggc 7320 catagtatca aggaacttct ttttttccgt ggtggtatca acatgataat tatgattatc 7380 atgatgg 7387 18 32 DNA Artificial Sequence Description of Artificial Sequence artificial sequence 18 gggcccgcta gcatgaaaca acaagaaaca gt 32 19 30 DNA Artificial Sequence Description of Artificial Sequence artificial sequence 19 cccggggtcg acctttgtcg aatccttccc 30 20 6204 DNA Leuconostoc mesenteroides 20 gctagcatga aacaacaaga aacagttacc cgtaaaaaac tttataaatc cggtaaggtt 60 tgggttgcag cagctactgc atttgcggta ttgggggttt caactgtaac aacagtccat 120 gcggatacaa attcgaatgt cgctgttaag caaataaata atacaggaac caatgattct 180 ggcgaaaaaa aggtaccggt tccatcaact aataatgata gtttgaagca aggaacagat 240 ggtttttggt atgattcaga cggcaatcgt gtcgatcaga agaccaatca gattctgctt 300 actgcggaac aacttaaaaa aaataacgaa aaaaatttat cagtaatcag tgatgataca 360 tcaaaaaaag atgatgaaaa tatttctaag cagaccaaaa ttgctaatca acaaacagta 420 gatactgcta aaggcctgac taccagtaat ttatctgatc ccatcactgg gggtcactat 480 gaaaatcaca atggctactt tgtttatata gatgcttcag gaaaacaagt aacaggtttg 540 caaaatattg atggtaattt acaatatttt gatgacaatg gatatcaagt caagggatcc 600 ttccgagatg tcaacggcaa gcatatctat tttgattcag taacagggaa agctagttca 660 aatgttgata ttgttaacgg taaagctcaa ggatatgatg cgcaaggcaa ccaattaaag 720 aaaagttatg tcgccgatag ttctgggcaa acttactatt ttgatggtaa tggccaaccg 780 ttaatcggct tgcaaacaat tgatgggaac ctacaatatt ttaaccaaca aggggttcaa 840 ataaagggtg gtttccaaga tgttaacaat aaacgtattt attttgcacc aaacacaggt 900 aatgccgttg ccaatactga aataattaac ggtaaattac aggggcgtga cgcaaatggt 960 aaccaggtaa agaatgcatt tagtaaagat gttgcaggaa atacatttta ttttgacgca 1020 aacggtgtga tgttaacagg gttgcaaact atttcaggaa agacatatta tcttgatgaa 1080 caaggacacc tgagaaaaaa ttacgcggga acattcaata atcagtttat gtacttcgat 1140 gctgatacag gtgcgggtaa aacagcgatt gaatatcaat ttgatcaagg attggtatca 1200 caaagtaatg aaaatactcc tcacaatgcc gcaaagtctt atgataaaag tagttttgaa 1260 aatgttgatg gttacttaac agcagataca tggtatcgtc caaccgatat tttaaaaaat 1320 ggagatactt ggacggcatc taccgaaact gatatgcgtc cgcttttaat gacatggtgg 1380 cctgacaaac aaacacaagc aaattacttg aattttatgt ctagtaaagg acttggtata 1440 acgaccactt atacagcagc tacgtcacaa aaaacactaa atgacgcagc ctttgttatt 1500 caaacagcaa ttgaacaaca aatatctttg aaaaaaagta ctgagtggtt acgtgatgca 1560 attgatagtt ttgtgaagac gcaagctaat tggaataagc aaacagaaga tgaagctttc 1620 gatggtttgc agtggcttca agggggattc ctagcttatc aagatgattc acatcggacg 1680 ccgaatactg attcaggaaa taacagaaaa ctaggacgtc aaccaattaa tatcgatggt 1740 tcgaaagata caactgatgg taaaggctct gaattcttat tagctaacga tattgacaac 1800 tcaaatccga ttgttcaagc tgagcaatta aactggctac actatttaat gaattttggt 1860 agtattacag gtaataatga caatgcgaat tttgatggca ttcgtgtaga tgctgttgat 1920 aatgttgatg ctgatttact aaaaatagct ggcgattatt ttaaagctct atatggtaca 1980 gataaaagcg acgccaatgc caataagcat ttgtctattt tagaagactg gaacggtaaa 2040 gatcctcagt atgttaatca acagggcaat gcgcaattaa caatggatta cacagttact 2100 tcacagtttg gcaattctct aacacatggc gccaacaaca ggagtaacat gtggtatttc 2160 ttagatactg gctattatct taatggagat cttaataaga agatagtaga taagaaccgt 2220 ccaaattctg gcactttggt taacagaatt gctaattcag gtgatacaaa agttattcca 2280 aattatagtt ttgttagagc acatgattac gatgctcaag atccaattag aaaagccatg 2340 attgatcatg gtattattaa aaacatgcag gatactttca cttttgacca actggctcag 2400 ggaatggaat tctactataa agatcaagag aatccgtctg gtttcaaaaa gtataacgat 2460 tataacttac ctagtgctta tgcaatgttg ttgactaata aggatactgt acctcgtgtc 2520 tattatggag atatgtacct cgaaggcggg caatatatgg aaaaagggac gatttacaat 2580 cctgtcattt cagcgttgct caaagctaga ataaaatatg tttctggtgg gcaaacaatg 2640 gctaccgata gttctggaaa agaccttaaa gatggcgaaa ctgatttgtt aacaagtgtt 2700 cgatttggta aaggaattat gacatcagat caaaccacaa cacaagacaa tagccaagat 2760 tataaaaatc aaggcatcgg tgtcattgtt ggtaataacc ctgaccttaa gttgaacaat 2820 gataagacca ttaccttgca tatgggaaag gcgcataaga atcaacttta ccgtgcctta 2880 gtattatcaa atgactcagg aattgatgtt tatgatagtg atgataaagc accaactttg 2940 agaacaaatg acaacggtga cttgattttc cataagacaa atacgtttgt gaagcaagat 3000 ggaactatta taaattacga aatgaaggga tcattaaatg ctttaatttc aggttattta 3060 ggtgtctggg tgccagttgg agctagtgat tcacaagatg ctcgtacagt ggcaactgag 3120 tcatcatcaa gtaatgatgg ttctgtattc cattcaaatg ctgcattaga ttctaatgtt 3180 atatatgaag gcttttcaaa ctttcaagcg atgccgactt ctcctgagca aagtacaaat 3240 gttgttattg caacaaaggc taacttattt aaagaattag gtattactag ttttgagtta 3300 gcacctcaat ataggtctag tggtgacact aattacggtg gcatgtcatt cttagattct 3360 ttcttaaata atggttatgc atttaccgat agatatgatt taggctttaa caaagcagac 3420 gggaatccta acccaacaaa gtatggaaca gatcaagatt tacgtaatgc aatagaggca 3480 ttacacaaaa acggcatgca ggctatagct gattgggttc ctgaccaaat atatgcttta 3540 ccaggaaagg aagttgttac cgctactaga gtagacgaac ggggaaatca actaaaagac 3600 acagattttg tcaacttact ctatgttgct aatactaaaa gtagtggtgt ggattatcag 3660 gcaaagtatg gcggcgaatt tttagataaa ttaagagaag agtacccatc gttattcaaa 3720 cagaaccaag tatcgacagg tcagccaatt gatgcttcta caaaaattaa gcaatggtca 3780 gctaaatata tgaatgggac caatatttta catcgaggtg cttattatgt tttgaaagac 3840 tgggctacta accagtattt taacattgca aaaacgaatg aagtattttt gccactacag 3900 ttgcagaata aagatgcgca aactggtttc attagtgatg cctccggtgt aaaatattac 3960 tcaattagtg gttatcaagc aaaagatact tttattgaag atggtaatgg gaattggtat 4020 tactttgata aagatggtta catggtgcgt tcgcagcaag gagaaaatcc tataagaaca 4080 gtcgaaacta gtgtcaacac acgaaacggt aattattact ttatgccaaa tggtgtcgag 4140 ttgcgcaaag gctttggaac ggataatagt ggtaatgtct attattttga tgatcaaggt 4200 aagatggtga gagataaata cattaacgat gatgctaata atttttatca cttaaatgtt 4260 gatgggacta tgtctcgagg actatttaaa tttgattctg atactctaca gtattttgct 4320 agtaatggtg tccaaataaa agatagttat gcgaaggata gtaaaggcaa taaatattat 4380 tttgactcag ctacaggaaa taacgatact gggaaagccc aaacttggga tggtaatggc 4440 tactatatta ctattgattc tgatgcgaac aatacaattg gggttaacac agactacact 4500 gcctacatca ctagctcgct gcgcgaagat ggcttatttg ctaacgcacc ttacggtgtt 4560 gtaacaaaag accaaaatgg taacgatctt aagtggcagt atattaacca tacgaaacag 4620 tacgaagggc aacaagtgca agtcacgcgt caatacacag acagtaaggg agtcagctgg 4680 aacttaatta cctttgctgg tggtgattta caaggacaaa ggctttgggt ggatagtcgt 4740 gcgttaacta tgacaccatt taaaacgatg aaccaaataa gcttcattag ttatgctaac 4800 cgcaatgatg ggttgttttt gaatgcgcca taccaagtca aggggtatca attagctggg 4860 atgtccaacc aatacaaggg ccaacaagtg accattgctg gggtggcgaa cgtttctgga 4920 aaagactgga gtctgattag ttttaatggg acacagtact ggattgatag tcaggcattg 4980 aataccaatt tcacacatga catgaaccaa aaggtctttg tcaatacaac tagtaatctt 5040 gatgggttat tcttaaatgc gccataccgt caaccgggtt ataagttagc cggtttggct 5100 aaaaattaca acaaccaaac ggttactgtt agtcaacagt actttgatga tcaaggcacg 5160 gtctggagtc aggttgtcct tgggggtcag acggtctggg ttgataacca tgcattggca 5220 cagatgcaag ttagtgatac agaccaacag ctctatgtga atagcaatgg tcggaatgat 5280 gggttattct tgaatgcgcc atatcgtggt caagggtcac aactgatagg catgacggca 5340 gattataatg ggcaacatgt acaagtgacc aagcaagggc aagatgccta tggtgcacaa 5400 tggcgtctta ttacgctaaa taatcaacag gtctgggttg atagtcgcgc tttgagcaca 5460 acaatcatgc aagccatgaa tgataatatg tatgtaaata gcagccaacg gacagatggc 5520 ttgtggttaa acgcacctta tacgatgagt ggggctaaat gggctggtga tacacgttca 5580 gctaatgggc gctatgtcca tatttcaaaa gcttattcaa acgaagtcgg caatacatat 5640 tacttgacga atttgaatgg tcaaagcaca tggattgaca agcgggcgtt tactgtgacc 5700 ttcgatcagg tggtggcatt aaatgcaacg attgtggcac gccaacgacc agatgggatg 5760 tttaagacag caccatatgg tgaagcgggg gcgcagtttg tcgattatgt gacaaactat 5820 aaccagcaaa ccgtgccagt aacaaagcaa cattcagatg ctcaggggaa tcaatggtac 5880 ttagcgacag tgaatgggac acaatactgg attgatcaac ggtcattttc accagtagta 5940 acgaaggtgg ttgattatca agctaagatt gtgccacgga caacacgtga tggtgtgttt 6000 agtggcgcac cctatgggga agtgaatgct aagctagtta acatggcaac tgcgtatcaa 6060 aatcaagttg tccatgcgac aggggaatat acgaatgctt cagggatcac atggagtcag 6120 ttcgcgttaa gcgggcaaga agacaagcta tggattgata agcgtgcttt gcaagcttaa 6180 gggaaggatt cgacaaaggt cgac 6204 21 7 PRT Artificial Sequence Description of Artificial Sequence artificial sequence 21 Asp Thr Asn Ser Asn Val Ala 1 5 22 5 PRT Artificial Sequence Description of Artificial Sequence artificial sequence 22 Met Lys Gln Gln Glu 1 5 23 5 PRT Artificial Sequence Description of Artificial Sequence artificial sequence 23 Lys Lys Val Pro Val 1 5 24 5 PRT Artificial Sequence Description of Artificial Sequence artificial sequence 24 Lys Asp Asp Glu Asn 1 5 25 5 PRT Artificial Sequence Description of Artificial Sequence artificial sequence 25 Ile Asp Gly Asn Leu 1 5 26 5 PRT Artificial Sequence Description of Artificial Sequence artificial sequence 26 Tyr Val Ala Asp Ser 1 5 27 5 PRT Artificial Sequence Description of Artificial Sequence artificial sequence 27 His Leu Arg Lys Asn 1 5 28 5 PRT Artificial Sequence Description of Artificial Sequence artificial sequence 28 Asn Glu Asn Thr Pro 1 5 29 5 PRT Artificial Sequence Description of Artificial Sequence artificial sequence 29 Asn Val Asp Gly Tyr 1 5 30 5 PRT Artificial Sequence Description of Artificial Sequence artificial sequence 30 Asn Pro Asp Leu Lys 1 5 31 5 PRT Artificial Sequence Description of Artificial Sequence artificial sequence 31 Ser Asn Asp Ser Gly 1 5 32 5 PRT Artificial Sequence Description of Artificial Sequence artificial sequence 32 Asn Thr Phe Val Lys 1 5 33 5 PRT Artificial Sequence Description of Artificial Sequence artificial sequence 33 Ile Ser Gly Tyr Leu 1 5 34 5 PRT Artificial Sequence Description of Artificial Sequence artificial sequence 34 Ser Asn Ala Ala Leu 1 5 35 5 PRT Artificial Sequence Description of Artificial Sequence artificial sequence 35 Arg Gln Tyr Thr Asp 1 5 36 5 PRT Artificial Sequence Description of Artificial Sequence artificial sequence 36 Gln Leu Tyr Arg Ala 1 5 37 5 PRT Artificial Sequence Description of Artificial Sequence artificial sequence 37 Asp Asp Lys Ala Pro 1 5 38 5 PRT Artificial Sequence Description of Artificial Sequence artificial sequence 38 Thr Arg Gln Tyr Thr 1 5 39 5 PRT Artificial Sequence Description of Artificial Sequence artificial sequence 39 Ile Thr Phe Ala Gly 1 5 40 5 PRT Artificial Sequence Description of Artificial Sequence artificial sequence 40 Asn Gln Tyr Lys Gly 1 5 41 5 PRT Artificial Sequence Description of Artificial Sequence artificial sequence 41 Leu Phe Leu Asn Ala 1 5 42 5 PRT Artificial Sequence Description of Artificial Sequence artificial sequence 42 Gln Val Ser Asp Thr 1 5 43 5 PRT Artificial Sequence Description of Artificial Sequence artificial sequence 43 Leu Ile Thr Leu Asn 1 5 44 5 PRT Artificial Sequence Description of Artificial Sequence artificial sequence 44 Gly Arg Tyr Val His 1 5 45 5 PRT Artificial Sequence Description of Artificial Sequence artificial sequence 45 Thr Ala Pro Tyr Gly 1 5 46 5 PRT Artificial Sequence Description of Artificial Sequence artificial sequence 46 Val Val Asp Tyr Gln 1 5 47 5 PRT Artificial Sequence Description of Artificial Sequence artificial sequence 47 Leu Ser Gly Gln Glu 1 5 48 26 DNA Artificial Sequence 48 tctagactgc aaaatggcaa ctacta 26 49 26 DNA Artificial Sequence Description of Artificial Sequence artificial sequence 49 gtcgacggtt tcatttggag tagtta 26 50 276 DNA Solanum tuberosum 50 atggcaacta ctaaatcttt tttaatttta ttttttatga tattagcaac tactagttca 60 acatgtgcta agttggaaga aatggttact gttctaagta ttgatggagg tggaattaag 120 ggaatcattc cagctatcat tctcgaattt cttgaaggac aacttcagga agtggacaat 180 aataaagatg caagacttgc agattacttt gatgtaattg gaggaacaag tacaggaggt 240 ttattgactg ctatgataac tactccaaat gaaacc 276 51 31 DNA Artificial Sequence Description of Artificial Sequence artificial sequence 51 gcgtactcta gacgtactcc gccatgacca c 31 52 30 DNA Artificial Sequence Description of Artificial Sequence artificial sequence 52 gcgtacgtcg acggccctga tgggtcccat 30 53 34 DNA Artificial Sequence Description of Artificial Sequence artificial sequence 53 ggccgggtcg acgatacaaa ttcgaatgtc gctg 34 54 33 DNA Artificial Sequence Description of Artificial Sequence artificial sequence 54 ggccggctgc aggttaccct cctttgtcga atc 33 

What is claimed is:
 1. An isolated nucleic acid molecule selected from the group consisting of (a) nucleic acid molecules encoding at least the mature form of a protein comprising the amino acid sequence indicated in SEQ ID No. 2 or the amino acid sequence which is encoded by the DNA contained in plasmid DSM 12666; (b) nucleic acid molecules comprising the nucleotide sequence indicated in SEQ ID No. 1 or the nucleotide sequence of the DNA contained in plasmid DSM 12666 or a corresponding ribonucleotide sequence; (c) nucleic acid molecules encoding a protein, the amino acid sequence of which has a homology of at least 80% to the amino acid sequence indicated in SEQ ID No 2; and (d) nucleic acid molecules, the nucleotide sequence of which deviates on account of the degeneracy of the genetic code from the sequence of the nucleic acid molecules as defined in (a), (b) or (c), wherein said nucleic acid molecule encodes an alternansucrase that catalyzes the conversion of sucrose to alternan.
 2. A vector containing a nucleic acid molecule according to claim
 1. 3. The vector according to claim 2, wherein the nucleic acid molecule is connected in sense orientation to regulatory elements ensuring the transcription and synthesis of a translatable RNA in prokaryotic or eukaryotic cells.
 4. Plasmid pAlsu-pSK deposited under the accession No. DSM
 12666. 5. A host cell transformed with a nucleic acid molecule of claim 1 or a vector of claim 2 or 3 or a cell descended from such a transformed host cell, wherein said descendant retains the introduced nucleic acid molecule or vector.
 6. The host cell according to claim 5, which is a cell of a microorganism.
 7. The host cell according to claim 5, which is an E. coli cell.
 8. A method for preparing a protein that catalyzes the conversion of sucrose to alternan, wherein a host cell of claim 5 is cultured under conditions permitting the synthesis of the protein, and wherein the protein is isolated from the cultured cells and/or the culture medium.
 9. A transgenic plant cell transformed with a nucleic acid molecule of claim 1 or a vector of claim 2 or 3, or a plant cell descended from such a cell, wherein said nucleic acid molecule encoding a protein that catalyzes the conversion of sucrose to alternan is under the control of regulatory elements permitting the transcription of a translatable mRNA in plant cells, wherein said descendant retains said nucleic acid molecule or vector.
 10. A plant containing the plant cell of claim
 9. 11. The plant according to claim 10, which is a plant that is cultivated for nutrition or a technical purpose.
 12. The plant according to claim 10, which is a sugar-storing or starch-storing plant.
 13. Propagation material of a plant according to claim 12, wherein said propagation material retains said nucleic acid molecule or vector.
 14. A method for preparing alternan comprising the steps of extracting and isolating the alternan from a plant according to claim
 12. 15. A method for preparing alternan and/or fructose, wherein (a) a host cell of claim 5 secretes an alternansucrase into a sucrose-containing culture medium; and (b) alternan and/or fructose is/are isolated from the culture medium.
 16. The method according to claim 15, wherein the host cell is immobilized.
 17. The plant according to claim 11, wherein said plant is selected from the group consisting of rye, maize, barley, oat, wheat, rice, pea, cassava, potato, rape, sunflower, soybean, flax, hemp, cotton, sugar cane, sugar beet, alfalfa, clover, ryegrass, tomato, lettuce, and chicory. 